Frost Hardiness

Plants vary in their ability to tolerate cold temperatures and harsh conditions. Different areas in Colorado can have drastically different climates and varying weather conditions each year. All of these factors make it difficult to determine a “safe date” to plant.

We have complied a list of plants ranging from “Very Hardy” to “Tender”. We offer recommendations on planting dates in the Denver area for each group but caution that these dates are approximations. We strongly recommend hardening off your plants (especially annuals) before planting and keeping a close eye on the weather. If needed, covering plants during cold snaps or chilly nights can help protect them.

Very Hardy Plants

Very hardy plants can typically be planted 7 weeks before the average last frost date. In the Denver Metro Area, this is usually after April 1st.

Very Hardy Flowers

Alyssum
Anchusa
Centaurea
Dracaena
Dusty Miller
Larkspur
Pansy
Snapdragon
Sweet Pea
Viola

Very Hardy Vegetables

Asparagus
Fennel
Onions
Peas
Potato
Radish
Strawberries

Hardy Plants

Hardy plants can typically be planted 5 weeks before the average last frost date. In the Denver Metro Area, this is usually after April 20th.

Hardy Flowers

Arctotis
Artemesia
Baby Blue Eyes
Bellis
Calendula
Carnation
Cerastium
Columbine
Dianthus
Diascia
Erysimum
Flowering Kale
Heuchera
Iberis
Lavender
Lenten Rose
Lobelia
Lupine
Matricaria
Myosotis
Nemesia
Osteospermum
Phlox
Roses
Vinca Vine

Hardy Vegetables

Broccoli
Brussels Sprouts
Cabbage
Cauliflower
Kohlrabi
Lettuce
Pak Choi
Perennial Herbs
Radicchio
Rhubarb
Spinach

Half Hardy Plants

Half hardy plants can typically be planted 3 weeks before the average last frost date. In the Denver Metro Area, this is usually after May 1st.

Half Hardy Flowers

Anagallis
Angelonia
Bacopa
Bells of Ireland
Calibrachoa
California Poppy
Campanula
Coreopsis
Cosmos
Datura
Delphinium
Dichondra
Euphorbia
Felicia Daisy
Gazania
Gerbera
Gomphrena
Lotus Vine
Mexican Feather Grass
Ornamental Grasses
Pennisetum
Penstemon
Petunia
Phlox
Pincushion Flower
Regal Geranium
Ruby Grass
Rudbeckia
Sanvitalia
Stocks
Strawflower
Sutera
Sweet Pea
Trifolium
Verbena

Half Hardy Vegetables

Artichoke
Celery
Leek

Tender Plants

Tender plants can be planted when there is no longer danger of frost. In the Denver Metro Area, this is usually after May 20th.

Tender Flowers

Abutilon
Achimenes
Ageratum
Alternanthera
Alternaria
Amaranthus
Angelonia
Argyranthemum
Asparagus Fern
Aster
Banana
Balsam
Begonia
Bidens
Bouganvilla
Bower Vine
Brachycome
Browallia
Brunfelsia
Caladium
Calibrachoa
Calla Lily
Callopsis
Campanula
Canna
Cardinal Climber
Celosia
Chrysanthemum
Chrysocephalum
Cigar Plant
Clematis
Cleome
Coleus
Cordyline
Coreopsis
Crassula
Crossandra
Cuphea
Dahlberg Daisy
Dahlia
Dallas Fern
Daylily
Dipladenia
Elephant Ears
Evolvulus
Ferns
Fiber Optic Grass
Four O’Clock
Fuchsia
Geranium
Gloriosa Lily
Guara
Heliotrope
Hibiscus
Impatiens
Iresene
Iris
Jasmine
Lantana
Lisianthus
Livingstone Daisy
Lothospermum
Lysmachia
Mandevilla
Marguerite Daisy
Marigolds
Mecardonia
Melampodium
Millet
Mimulus
Moon Vine
Monopsis
Morning Glory
Napa Valley Fern
Nasturtium
Nemesia
Nicotiana
Nierembergia
Nolana
Oleander
Oxalis
Pampas Grass
Pentas
Periwinkle
Perilla
Plectranthus
Polka Dot Plant
Polygonum
Portulaca
Rudbeckia
Salpiglopssis
Salvia
Scarlet Runner Bean
Scaevola
Schizanthus
Sedum
Statice
Streptocarpella
Sunflower
Swan River Daisy
Sweet Potato Vine
Tithonia
Thumbergia
Torenia
Trachelium
Trailing Portulaca
Tropical Hibiscus
Tropical Water Plants
Veronica
Vinca
Zinnia

Tender Vegetables

Annual Herbs
Cantaloupe
Corn
Cucumber
Eggplant
Okra
Peanuts
Peppers
Pumpkin
Squash
Tomato
Watermelon

Hardening Off Annuals

HOW TO HARDEN OFF YOUR PLANTS

The gradual process of hardening off is a crucial one, like the slow but steady  way we brace our entry into a chilly lake in summer. Jumping in all at once is a shock to our system, but if we start by sticking a toe in and slowly working our way in, the total immersion is not nearly so stressful.

Plants need a period of time to get used to their new homes.  The adjustment period is called “hardening off.”  We recommend a hardening off period of about three to five days.  This will give the foliage tissue time to toughen up so the plants don’t go into shock.

COLD SPRING WEATHER

1.   Put new plants outside in a place that is protected from sun and wind.  Make sure they get watered as needed.

2.   If nights will be cooler than 38-40 degrees, bring into the garage or house.

3.   Move the plants out a littler farther each day toward the place in which they will be growing.

4.   Leave the plants out at night unless there will be low temperatures.  They still might need covering at night if there is a drastic change in the weather.

5.   Plant on a cloudy day and they will take right off.  Using a root stimulator when planting will help.

WARM SPRING WEATHER

The process above can be sped up, but it is basically the same.

HOT WEATHER

The process here is somewhat different since you are acclimating your plants to hot sun and drying winds.

1.   Put plants in a cool, protected place for a day or two.

2.   Gradually move plants towards their new location over a period of three or four days.

3.   Plant in the cool of the evening or on a cloudy day.

4.   Be prepared to shade with a shingle or board until plants are settled in.

5.   Water as needed.  Always check the soil first.

Seed Starting 101

“To plant a seed is to
believe in tomorrow”

~ Audrey Hepburn

If you’re impatiently counting the days until spring arrives so you can start working on this year’s garden, there might be a way to get started on it a little sooner. Mid-February to early March is an ideal time to start your garden indoors by planting from seed. It’s easy, it’s fun, and it’ll make waiting for spring’s arrival a little easier. Ready to get started? Let’s dig in!

WHAT CROPS CAN YOU START NOW?
Most annual flowers and vegetable plants should be sown indoors about six weeks before planting outside. Leaf crops like spinach, lettuce, Swiss chard as well as cabbage, cauliflower, broccoli, peppers, eggplant and tomatoes can all be started indoors in late February and early March.

Different seed types require differing numbers of days to sprout and grow to transplant size. To be certain, consult the seed packet and then count backwards to figure out the date to sow your seed. Our Frost Hardiness List will help you find the best dates to plant in your particular area.  (Some crops are fussy about having their roots disturbed by transplanting. You may want to sow seeds for root crops like radishes, carrots, and beets directly outdoors after the last frost date has passed for your area.)

START WITH CLEAN SEED STARTING CONTAINERS
Seed starting flats are a popular choice for starting seeds that will help maximize the number of plants you can grow per tray. Some come with domes that help keep the soil surface moist while germinating. If you will be using previously used containers, be sure to clean and sanitize them thoroughly before you begin. Biodegradable fiber pots and trays can be another good choice, and peat pellets are a fun alternative to use — especially with children.

CHOOSE THE RIGHT SOIL
The right soil is critical to success. You’ll want to choose a soil that’s specifically formulated for starting seeds. Seeds need just the right amount of moisture, warmth, and air to germinate, and these specialty soils are light enough to support fledgling root systems to give your plants a healthy start. Don’t use outdoor garden soil, as it’s far too dense and heavy for delicate root systems.

PLANTING TIPS
Fill your containers with the seed starting media. Then, using a spray bottle, mist to moisten the soil evenly. Sprinkle the seeds about 1/4″ apart on the soil surface and barely cover them with soil. Water with a very gentle spray. It’s important not to let the soil dry out before the seeds sprout. A plastic dome cover helps keep the soil surface moist without disturbing the seeds. (TIP: Young seedlings look pretty much the same until they begin to develop “true” leaves. Do yourself a favor and label the seed flats from the beginning. It’s also a good idea to include the date you planted the seeds.)

KEEP THINGS COZY
Seeds also need warmth to germinate. Most seeds will germinate at room temperature, but some warm-season crops like peppers prefer it warmer. A propagation heating mat underneath the seed tray will help with quicker germination, more seedlings, and greater uniformity. After the seeds have sprouted, take them off the heat mat, remove the dome cover, and put them under fluorescent grow lights to keep them from becoming spindly. You can also place your brand new seedlings in a sunny window if you have room.

POTTING UP
When your seedlings are a couple inches tall, you’ll want to thin them by removing some of them. Then gently dig the remaining seedlings out with a fork, so as not to harm the roots. Carefully transplant them into slightly larger containers, so they’ll have more room to grow. Don’t step them up to a too large container too soon though! Choose a container that’s about twice the size of the seed cells (a 3″– 4″ pot size usually works great). Always be sure any plastic containers you choose have drainage holes in the bottom. If the leaves fade to pale green or yellow, feed the seedlings with a water-soluble fertilizer when watering.

GET READY TO PLANT OUTDOORS
Your pampered indoor seedlings will need to be properly acclimated to their new outdoor life! Before transplanting outdoors, begin the process of “hardening off” your plants. On a warm spring day, move the seedling containers to a protected place (such as a porch) for just a few hours, then bring them back indoors. Each day gradually increase your fledgling plants’ exposure to the outdoor environment. After several days, transplant them to their final growing space in the garden.

Starting plants from seed can be a great way to get a jump on Colorado’s all-too-short growing season, and it can give you more choices in growing heirloom or hard-to-find varieties of veggies and flowers. More than that, it can evoke a sense of wonder to start from a dry seed and watch it grow into a big beautiful plant for your garden. Try it!

When Can I Plant?

Here comes the sun! With it and the warm day temperatures of spring comes one of the most frequent questions we hear. “Can I plant this now?” The answer depends on the plant and particularly, on the nighttime temperatures. Our early spring days are often beautiful and daytime temperatures may reach well into the 70’s. It’s the night temperatures that really tell us when it’s safe to plant. Our last frost date is generally considered to occur around May 20th. While some years the date arrives earlier, there are occasional years when it occurs as late as June 1. We’re eager gardeners and antsy to get plants in the ground, but if we aren’t mindful of the night temperatures, we can do more harm than good.

Before I get carried away talking about plants, I should mention the value of hardening off your plants before you plant. What is hardening off? It’s a process that acclimates plants prior to transplanting in order to reduce the risk of transplant shock. The process takes a few days, but it’s worth the investment of time, particularly in early spring or late summer heat.

Day one, place the plants in a shaded area outside and move them indoors or into a garage that night. Day two, place the plants in partial sun for the day and move into the garage or indoors at night. Day three, place the plant in a sunny spot for the day and move to a protected outdoor location, like against the house or under a porch, for the night. Day four, move into the sun for the day and leave them in the exposed location for the night. Day five, plant.

In late summer, when the temperatures are well over 80°F, I often use the same process, but shortened to 3 days. This helps prevent sun and wind burn to the young plants. Hardening off plants increases successful transplanting.Using a Cloche to protect plants
Hardening Off Plants

Now back to what we can plant and when we can plant it. Hands down, the most common plants asked about are tomatoes and peppers. Tomatoes and peppers, two of the longest season garden vegetables, prefer night temperatures to be above 50°F for about a week before they are planted. The ground needs to be consistently warm for them to do well. If we plant too early, and the night temperatures are still cold, plants set less fruit and are often more susceptible to problems like blossom end rot later in the season.

There are helpful tools like Season Starters that can be used to warm the ground earlier than traditional planting would allow. They should be set up for 7-10 days to warm the soil, before they are planted with your seedlings. Once planted, the plant protectors act as insulators against cold temperatures, much like a mini greenhouse. Generally, Season Starters can give you a jump start by several weeks. Set them up about April 15 and you can plant inside them a week later.

We hope this Frost Hardiness list will help gardeners know when it is safe to set out their plants. The actual dates vary, of course, with each area, but the principle is the same. Perennials that are not hardy in Colorado are listed as annuals. The hardiness of perennials is based on coming out of a protected climate.

To obtain maximum frost hardiness, HARDEN PLANTS OFF gradually by exposing them to sun, wind, and cold, but above freezing temperatures
for a few days
.

These dates are approximate for the Denver area. Safe dates vary from year to year, suburb to suburb, and even from one location in the garden to another. Covering plants on unusually cold nights will help protect them. On extremely cold nights it may be necessary to dig plants up and bring them inside.

Very Hardy Plants–Plant Out up to 7 weeks
before last frost

(April 1 in Denver, April 10 in Golden & Parker)

Annuals:
Alyssum, Anchusa, Centaurea, Dracaena, Dusty Miller, Larkspur, Nigella, Pansy, Snapdragon, Sweet Pea

Perennial Starts
Achillea, Aegopodium, Ajuga, Aurinia, Arabis, Armeria, Aubretia, Basket of Gold, Bishop’s Weed, Carnation, Creeping Phlox, Gayfeather, Hardy Hibiscus, Lavender Cotton, Liatris, Lobelia, Primrose, Primula, Rock Cress, Purple Rock Cress, Red Hot Poker, Santolina, Sedum, Thyme, Torch Lily, Tritoma, Viola, Yarrow

Vegetable Plants
Asparagus, Chives, Fennel, Garlic, Onions, Peas, Potato, Radish, Strawberry

Hardy Plants–Plant up to 5 weeks before last frost
(April 20 in Denver, April 30 in Golden & Parker)

Annuals
African Daisy, Arctotis, Baby Blue Eyes, Calendula, Carnation, Dianthus, Diascia, Flowering Kale, Lobelia, Osteospermum, Phlox, Twinspur, Vinca Vine

Perennial Starts
Alstromeria, Anemone,Baby’ Breath, Bachelor Buttons, Bellis, Campanula, Candytuft, Centaurea, Cerastium, Columbine, Coral Bells, Coreopsis, Daylily, Dianthus, Digitalis, Doronicum, English Daisy, Erysimum, Festuca, Feverfew, Flax, Forget-Me-Not, Foxglove, Galium, Garden Mums, Gloriosa Daisy, Gypsophila, Helianthemum, Hemerocallis, Heuchera, Hollyhocks, Hosta, Iberis, Lavender, Lenten Rose, Lupine, Lunaria, Lysimachia, Maltese Cross, Matricaria, Mexican Feather Grass, Missouri Primrose, Money Plant, Myosotis, Oenothera, Painted Daisy, Penstemon, Tall Phlox, Pincushion Flower, Poppy, Pyrethrum, Roses, Rudbeckia, Scabiosa, Shasta Daisy, Snow-in Summer, Statice, Sweet William, Sweet Woodruff, Veronica, Violet

Vegetable Plants
Broccoli, Brussels Sprouts, Cabbage, Cauliflower, Kohlrabi, Lettuce, Pak Choi, Perennial Herbs, Radicchio, Rhubarb, Spinach

Half-Hardy Plants–Plant out up to 3 weeks before last frost date.
(May 1 in Denver, May 10 in Golden & Parker)

Annuals
Anagallis, Angelonia, Angel’s Trumpets, Bacopa, Bells of Ireland, Blue Lace Flower, Calibrachoa, California Poppy, Campanula, Clover, Coreopsis, Cosmos, Creeping Zinnia, Datura, Dichondra, Didiscus, Fountain Grass, Gaillardia, Gazania, Gerbera, Gloriosa Daisy, Gomphrena, Lotus Vine, Ornamental Grasses, Petunia, Pennisetum, Phlox, Purple Bell Vine, Regal Geranium, Ruby Grass, Rudbeckia, Sanvitalia, Scarlet Pimpernel, Stocks, Strawflowers, Steirodiscus, Sutera, Sweet Peas, Sweet Sultan, Transvaal Daisy, Trifolium, Verbena, Xerianthemum


Perennial Starts
Artemesia, Hardy Asters, Astilbe, Balloon Flower, Bee Balm, Bleeding Heart, Delphinium, Echinacea, Euphorbia, Felicia Daisy, Geum, Gladiolus, Hibiscus, Hypericum, Monarda, Peony, Platycodon, Purple Coneflower, Roses, Salvia, Sagina, Saxifraga, Verbena

Vegetable Plants
Artichoke, Celery, Leek

Tender Plants–Plant outside after almost all danger
of
frost has passed.
(May 20 in Denver, May 30 in Golden & Parker)

Annuals
Abutilon, Achimenes, African Daisy, Ageratum, Argyranthemum, Alternanthera, Alternaria ,amaranthus, Asparagus Fern, Asters, Axilflower, Balsam, Banana, Begonia, Bidens, Black Eyed Susan, Bloodleaf, Blue Throatwort, Bougainvillea, Bower Vine, Brachycome, Browallia, Brunfelsia, Caladium, Calla Lily, Calliopsis, Canna, Cardinal Flower, Catharanthus, Celosia, Chrysanthemum, Chrysocephalum, Cigar Plant, Cleome, Coleus, Copperleaf, Crassula, Crossandra, Cuphea, Dahlberg Daisy, Dahlia, Dallas Fern, Dipladenia, Elephant Ears, Evolvulus, Fanflower, Fiber Optic Grass, Flowering Maple, Flowering Tobacco, Fountain Grass, Four O’ Clock, Fuchsia, Geranium, Gloriosa Lily, Firebush, Guara, Hamelia, Heliotrope, Hibiscus, Impatiens, Iresene, Jasmine, Lantana, Livingstone Daisy, Lisianthus, Lithospermum, Marguerite Daisy, Marigold, Mecardonia, Melampodium, Millet, Mimulus, Monkey Flower, Moon Vine, Morning Glory, Napa Valley Fern, Nasturtium, Nemesia, Nicotiana, Nierembergia, Nolana, Oleander, Oxalis, Painted Tongue, Pampas Grass, Pentas, Perilla, Periwinkle, Plectranthus, Polka Dot Plant, Polygonum, Portulaca, Salpiglossis, Salvia, Sanvitalia, Scarlet Runner Bean, Scaevola, Scutellaria, Schizanthus, Skullcap, Statice, Stoneseed, Streptocarpella, Sunflower, Swan River Daisy, Sweet Potato Vine, Thunbergia, Tithonia, Torenia, Trachelium, Trailing Portulaca, Tropical Hibiscus, Tropical Water Plants, Zinnia

Vegetable Plants
Annual Herbs, Cantaloupe, Corn, Cucumber, Eggplant, Okra, Peanut, Bell & Chile Peppers, Pumpkin, Squash, Sweet Potato, Tomato, Watermelon

Sunny Summer Blooms

 

Spring flowers may have faded, but that doesn’t mean you garden has to lack color! There are many perennials that bide their time growing strong root systems throughout spring so they can put on their own show in the heat of summer. Here are several varieties that provide a beautiful summer display:

Coreopsis, also known as tickseed, starts blooming in June and is easy to grow. With some deadheading, it will continue to bloom with its bright, daisy-like flowers until fall. We have many varieties available ranging from cream colored to bright yellow and even red! Most range in size from 12” to 32” tall. ‘Full Moon’ has gorgeous, buttery yellow flowers held on wiry stems above bright green foliage and reaches up to 30” tall and 24” wide. ‘Moonbeam’ is a thread leaf variety with feathery foliage and creamy yellow flowers. It reaches to 18” tall and wide. Coreopsis pairs well with blue and purple flowering plants with a more spikey texture such as salvia, catmint, and lavender.

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Hardy Hibiscus, with its large, tropical looking flowers and foliage is a showstopper in the late summer garden! While it’s a late starter, once it pops out of the ground it grows incredibly fast. Its sturdy stems and large leaves support enormous hibiscus flowers in shades of red, pink, or white in July and August. The stems will die back to the ground in late fall at which time it should be cut back. ‘Mars Madness’ is a variety with red-tinged leaves that emerge lime green and has bright red flowers. ‘Tie Dye’ has bright green leaves and has pink and white bicolor flowers with a ruby throat. With extra water, time, and care this plant can reach 5 feet tall and wide, but usually they will be 30” to 48” tall and wide in our area. Plant Hardy Hibiscus at the back of the perennial border or among perennials that have finished blooming such as peonies or tall bearded iris.hardy hibiscus

Rudbeckia, also known as Gloriosa Daisy or Black-Eyed Susan, produce large yellow to gold daisy-like flowers. ‘Prairie Sun’ grows to 36” tall and 18” wide with large blooms of lemon-yellow tipped gold petals and a green eye. ‘Indian Summer’ has large, bright yellow flowers with a dark eye and also grows to 36” tall and 18” wide. Rudbeckia looks wonderful planted in mass. Use it in borders, cottage gardens, meadows, or for naturalizing. Butterflies love it!

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Baby’s Breath (Gypsophila paniculata) has airy plumes of white flowers at the ends of the stems in July and August and provides a delicate texture to the garden. It grows to approximately 32” tall and wide with a dense mounded form. The silvery-blue narrow leaves look good all season and the flowers are excellent for cutting. It is drought tolerant. Deadhead to encourage fall bloom. Plant with iris, tulips, Oriental poppies, yarrow, and of course, roses. Choose location carefully as this one doesn’t like to be transplanted.

Hopflower Oregano (origanum rotundifolium) variety ‘Kent Beauty’ is a low, mounding form of ornamental oregano with long blooming cream and pink bracts containing tiny lavender flowers. The lush silvery-green foliage looks attractive all summer. Hopflower Oregano looks wonderful trailing over rocks or walls, in containers or in the front of the flowerbed. Bees love it!

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Cupid’s Dart (Catananche caerulea), also known as Love Plant, has 1” to 2” vivid blue flowers atop tall wiry stems that sway of its green rosette of leaves at the base. It blooms from summer until fall and is drought tolerant once established. Excellent as a cut flower or dried for arrangements, these blue daisies provide contrast in both the flower bed and in containers.cupids dart

Tall Garden Phlox (Phlox paniculata) comes in many colors from blue, pink, white, purple to bicolored flowers. This knee high, old-fashioned favorite blooms for six weeks or more beginning in late June. ‘Laura’ has beautiful lavender flowers offset with a white eye and reaches 30”-35” tall and 24” wide. At 18” tall and 24” wide, ‘Flame Red’ and it’s siblings in the Flame series provide a long blooming alternative to the taller varieties. Most varieties grow to 2’ to 3’ tall and provide a colorful transition between large background plants and smaller, front of the garden show-offs.Garden Phlox

Easy Combos for Hanging Baskets

Supertunia BordeauxHanging baskets can be a quick and easy way to add color and style to a patio or porch, but it’s important to select the right plants for the spot you have chosen. A basket of petunias is never going to be happy in a shady nook, and tuberous begonias will crisp up in the afternoon sun. When choosing plants, you also want to consider how easy it will be to water. If watering the basket is going to be a challenge, you can help compensate by choosing plants that can take dry conditions, or choose larger pots or self-watering pots and soil amendments that will help you maintain moisture around the root zone.DSC_4868

Available sunlight is the starting point for all plant selection, so it’s important to determine the number of hours your plants will receive in the location you plan to plant. Do you have a northern exposure or heavy shade from a tree? It doesn’t matter if “it’s really very bright!”—you will have poor performance from sun lovers like petunias. Our visual perception of light isn’t necessarily an accurate measurement of available light to the plant.
Full sun is 6+ hours of direct sun that will shine on the foliage of your plants, each day. These are going to generally be southern, western, or south-western sides of the house, and not tucked back under an awning. If it’s a spot you want to avoid in the middle of the afternoon, odds are good that it’s the perfect spot for a basket of upright geraniums or calibrachoa.
Easy plants for sunny baskets include petunias, scaevola, calibrachoa, trailing portulaca, lantana, trailing verbena, and bidens. A blend of petunias, verbena, and bidens will provide a mix of both colors and textures with long-blooming flower power. An easy care combo for full sun could include a salmon geranium, 3 ‘Bombay Blue’ scaevolas, and 3 light-yellow calibrachoas.

Part-Sun is less than 6 hours of sun per day, which typically amounts to morning sun only. These are usually eastern exposures or an area that would have all day sun, if it weren’t for that gorgeous maple planted two owners ago. An area with dappled shade for the full day can be counted as part-sun for planting purposes.bacopa basket

Easy plants for morning sun include New Guinea impatiens, torenia, many begonias, ivy geraniums, and bacopa. Bacopa can sometimes stop blooming at the peak heat of the summer, but the foliage remains as a lovely cascade and will bloom again once the temperatures cool a bit in late summer and fall. Pansies can also be included in this group, but like bacopa (and most of us!), high temperatures induce a resting phase. A quick and lovely part-sun combo might include a few yellow or salmon ‘Mocca Mix’ begonias, a few ‘Gold n Pearls’ bacopa, and a 4-pack of deep blue torenia.

Full Shade is quite literally no direct sun in a day. Common shade zones are under a porch or patio awning, under dense tree shade, or in the shade of buildings.begonia basket

An easy basket of shade-loving plants could include pansies, compact or trailing coleus, bacopa, begonias, fuchsia, and traditional impatiens. For a quick combo, try 3 Illumination begonias and 3 white bacopas.
With all basket plantings, it is important to monitor the growth of your plants so that you don’t end up with one vigorous plant taking over the entire pot (I’m looking at you, trailing petunias!). Mild, selective pinching and pruning throughout the summer will encourage new growth from the top of the basket and help keep your baskets looking full and fresh.

A word about feeding your plants – Yes! We’re asking our annuals to entertain us with beautiful blooms all summer long, through any sort of weather or challenge that comes their way. They can’t do that without regular fertilization. Try Jack’s Classic Blossom Booster for the majority of your flowering plants, outdoors and indoors. Petunias prefer a special diet, so try Jack’s Classic Petunia Feed. Follow the instructions on any fertilizer you select. Enjoy!

Some Like It Hot – and Sunny

Your patio bakes like the surface of the sun, you say? We can work with that! There are a number of annuals that are simply built and bred with extra heat tolerance, and it pays to know who’s who BEFORE July hits and your plants shrivel in protest. Try these heat-loving favorites from the start and by the time the heat settles in, you will have gorgeous plants that are ready to fight back.

Petunia Sanguna Radiant Rose
Petunia Sanguna Radiant Rose

Petunia
The ultimate annual for high-impact color! Petunias come in almost every color and there is a petunia for every need- mounding, trailing, or spreading. Old-school grandiflora plants have blossoms that can reach a diameter of 4” and newer choices include amazing color combinations, often on the same plant. Other innovations include varieties that do not require deadheading and shades that fade into a blend of colors (such as Indian Summer, which shows off yellow, peach, and orange flowers as the blossoms age).blooming-zinnias

Zinnia
Every garden should include some zinnias, whether tall or small, single or double. Zinnias are available in red, orange, yellow, pink, salmon, white, and magenta with heights ranging from 8” to 3’. Taller plants will provide cut flowers all summer! Both showy and durable, zinnias are an outstanding choice from seeds or starts.Geranium Indian Dunes

Geranium
Like petunias, geraniums can be traditional or modern. A classic red geranium in a terracotta pot will always be in style, but why not try a salmon variety with lime-green leaves? Another new introduction pairs crisp white and Kelly green leaves with scarlet petals, and still others have a blend of shades in each flower. The new interspecific varieties are bred for even more heat tolerance and the intense colors are eye-catching. A little bit old and a little bit new, geraniums have something for everyone… and they are easy to propagate to bring in for the winter.
marigolcMarigold
Just about everyone has grown a marigold from seed at some point, and it’s that ease that makes them so appealing. Diminutive dwarf varieties are great in the front of a bed and the taller French varieties are a solid choice for containers and vegetable gardens. For serious impact, try the large-flowering African types- plants can reach 2.5” and blossoms up to 5” across. Bees love marigolds, so expect to share your flowers. If not deadheaded regularly, marigolds are likely to re-seed themselves and become a permanent part of the landscape (for better or worse!)periwinkle
Periwinkle
Also known as vinca and available in white, pink, coral, red, magenta, and now deep purple. Great combination or filler plant and would do well in a border or container.

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Salvia
Annual salvias come in red, coral, white, lavender, deep purple, deep blue, and red/white. Some are tall (up to 3’!) and wispy, while others are more compact with a solid block of flower color. Depending on height and the desired look , salvias can function as either thrillers or fillers in a combination planting.portulaca

Portulaca
Portulaca can be upright or trailing and thrive in hot, dry spots. Flowers are 1-2” across and available in brilliant orange, yellow, magenta, cherry red, salmon, or white. Upright varieties are prolific self-seeders and may come back on their own each year. The trailing portulaca are less likely to re-seed and are outstanding in baskets or containers.cosmos

Cosmos
Available in white, pink, cerise, and chocolate, cosmos are a cheery addition to any sunny garden. They will self-seed aggressively and form maintenance-free meadows if left alone.calibrachoa

Calibrachoa
These are workhorse plants with massive flower power. Calibrachoas come in every color and unlike their petunia cousins, need NO deadheading at all. They are outstanding in containers and baskets and can be pruned back to create a bushy effect (rather than a cascade of color). They are an easy filler/spiller and can be tucked in almost anywhere when small. A rapid growth habit makes them knot together if planted in packs, so calis are typically sold as individual plants. This is balanced out by the size that one plant can achieve (fewer plants are needed).snapdragons

Snapdragon
A traditional favorite of children and the young-at-heart—who doesn’t love making the blossoms “snap”? This family includes both tall and small varieties, which makes snapdragons useful as either a thriller or filler. A row of ‘Rockets’ at the back of a bed will provide colorful height for the whole summer, and short-stuff ‘Montego’ plants are excellent for a more subtle effect. Snaps readily reseed themselves, so be prepared for volunteers in the spring (or be aggressive about cutting off spent flower spikes). Available in red, orange, yellow, white, pink, magenta, and burgundy.

Low Maintenance Annuals for Shade

acolg-e Coleus
Coleus is the amazing chameleon of the shady garden. It comes in a riot of colors, shapes, and textures and is equally at home in formal or unstructured areas. Large-leaf coleus such as the Kong series provide a sizable focal point, and the lacy Under The Sea series makes an exotic statement by itself. Coleus can even be a shady trailer (Meandering Linda) or tall backdrop. Try the brighter colors for the darkest areas to get a pop of color and the darker colors where you can see them close-up.
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Tuberous begonia
Show offs abound in this group! There is simply nothing subtle about these sizable plants with hot red, orange, yellow, salmon, white, or pink flowers. Leaves can be either green or deep purple, and several of the varieties are either trailing or pendulous, (the Illuminations series has 2” blossoms hanging like fruit). These plants are at their best in containers or hanging baskets.

 

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Wax Begonia
Wax begonias are a steady mainstay of shaded beds, but they can also handle sun. Flower colors are red, pink, or white and leaves can be either green or chocolate. Plants are uniformly compact and bushy with blooms all summer long. Truly a set-it-and–forget-it plant.

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Fuchsia
Nobody has ever accused a fuchsia of being drab! This family includes both upright and trailing varieties that can be used in beds, baskets, and containers. Flowers are typically bicolor (some pastels can give a white-on-white impression from afar). Fuchsia are outstanding for attracting hummingbirds and the blossoms are characteristically a teardrop shape with contrasting sepals. Petals are silken in appearance and may be red, pink, white, orange, or lavender. Classic and lovely, fuchsias are a worthy addition to any shady nook.ANGID
New Guinea Impatiens
These burly impatiens have larger leaves and flowers than their more delicate cousins. New Guineas are also resistant to Impatiens Downy Mildew, which makes them a perfect candidate to use in place of traditional impatiens. Unlike traditional impatiens, New Guineas are content with morning sun and will get to be a blocky 1’ x 1’ per plant—a great size for containers and beds. Try them anywhere you would have planted an old-school impatiens for an updated, floriferous burst of bright color.

atorkdbTorenia
Torenias are perfect for shady baskets, beds, or containers. Plants will trail if given an opportunity and mound in a flat area. Blossoms have a characteristic “wishbone” crossing of stamens and can be found in lavender, blue, magenta, white, and yellow. They are an excellent “filler” plant and do well in combination plantings.

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Lobelia
Lobelia is often at its best in the “shoulder seasons” of spring and early fall, though more heat-tolerant varieties appear every year. Colors range from sky blue to cobalt, with white, pink, and magenta options as well. Lobelias are available as an upright “bedder” plant and as a fluffy , trailing cloud of blues. Some newer varieties will take full sun, but most are happiest in part to full shade to prolong the bloom season. Flowers are delicate and attract butterflies.

 

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Pansy
Pansies are a wonderful cool-season choice for a shady area. Available in just about every color, pansies are a cheery sight in early spring and provide a burst of color in the fall. Flowers are larger than those of their perennial cousins, the violas, and can be found in both mixes of colors or single-color packs. Though usually dormant in the heat of summer, pansies can survive light snow cover and Icebreakers in particular are likely to come back in the spring.

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Oxalis
No, not that kind of oxalis—not the invasive, weedy variety that lives forever in sidewalk cracks. A well-chosen oxalis can be a gorgeous addition to a shade or part-sun container. Leaves range from green & purple to brilliant yellows and pinks with white, pink, or yellow flowers. Oxalis stays compact and would do well in a border or patio pot. Some varieties have very distinct color patterns and are best used in an area where they can be seen up-close.

Summertime Flower Power

pw containerTemperatures have warmed up.  We’ve had an abundance of rain.  Insects have recently hatched and are multiplying like mad.   So, how do you keep your plants looking fabulous through it all?  Plants have some built in defenses, but you can greatly help them along through stressful conditions.   It comes down to managing the moisture as best you can, and feeding them regularly, along with removing the spent blooms.

Managing moisture levels starts when the plants are potted.  The selection of the potting mix is the key to success.  This is definitely a year when drainage is the most important consideration.  Moisture control mixes tend to hold water for an extended period, which is helpful during dry periods but not so much when it rains.  mosture meter

It’s also important to feel the soil before watering.  Just like in most every other aspect of life, making assumptions are not a good idea.  Sometimes plants look as though they are wilting but they are really flagging due to high temperatures, reflective heat from nearby walls or concrete, or even because their root systems are so water logged leaving the plants unable to draw up moisture.  All the more reason to use a moisture meter or to get your fingers dirty and feel the soil.

Watering in the morning is better than watering in the heat of the day or in the evening.  Why?  When plants approach the day well hydrated, then they will be less stressed during the height of the heat of the day.  When plants are watered at night, it’s really a sort of recovery tactic.  Additionally, as moisture evaporates off the soils surface when the night temperatures cool, it’s the perfect set of condition for fungi like powdery mildew to take hold.  powdery mildew

One of the most important things you can do is fertilize your plants regularly.  If you are growing flowering annuals, choose a high phosphorus fertilizer, like Jack’s Classic Blossom Booster.  If you’ve ever wondered what those 3 numbers are on a package of fertilizer (ex.  10-30-15), they represent the percentage of the nitrogen, phosphorus and potash in the fertilizer.  The middle number represents the phosphorus which promotes flowering .  For flowering, this number should be 3 to 5 times higher than the first number, which represents the percentage of nitrogen to promote green growth.   Follow the directions on any fertilizer you choose.  Each is formulated differently and will have varied instructions for use.  We’re asking our plants to perform at their best during the most stressful part of the summer.  If we don’t supply them with the appropriate nutrition, they can’t live up to our expectations.  If you purchased a potting mix that said it included a fertilizer, it’s a good idea to supplement it around mid July.  More often than not, the fertilizer in the potting mix is just a little something to get things started and doesn’t support the plants for the long haul.  Jack's Classic Blossom BoosterLastly, a little selective pinching and dead-heading (removal of the spent blooms) will keep plants looking fresh.  Pinching and pruning stimulates new growth which brings new flowers, too.

Stressed Out Plants?

Rain, rain and more rain…….and hail.   Yes, we know we should be happy for the rain, since we know it will be well appreciated later this summer.  We should be enjoying the rain, right?  After all, most summers, rain is almost a novelty in Colorado.  Well, the novelty has worn off.  The ground is saturated in many areas, making it difficult to get things going in the garden. Your plants may even be exhibiting signs of stress from the excessive moisture. Brown mushy leaves and stems or gray-green. crispy leaves are both common signs of too much moisture. So, what can you do?

I apologize now if this sounds a bit preachy, but  we want to help you build your garden path, not lead you down the proverbial one.  The single most important thing to do for your garden is to amend the soil. Clay soils don’t allow roots to permeate through the particles and when water-logged roots don’t stand a chance. Amending the soil isn’t the glamorous, fun part of gardening, but it is the foundation for all we hope to grow. Build a good foundation and you’ll experience great results.  Prepare minimally and you can expect success relative to your efforts.  There are times in life where there simply is no substitute for going all out.  Preparing your soil is one of those times.  Often you won’t have a chance to do more than spotty amending between plants after the initial preparation.  In other words, there’s no going back.  Well, there is, but it requires a complete do-over and a tremendous amount of additional effort.  (stepping off the soap box now)nyc

What can you do for existing garden plants showing signs of distress?  Boomerang.   Just like the name suggests, it’s a “comeback” microbial-based formula for plants that helps relieve stressed root systems.  It is filled with nutrition that is easily absorbed by plants and encourages new root growth.  Most importantly, it really works.

BOOMERANGWith the abnormal amount of moisture there are a few undesirables visiting our gardens.  Slugs.  They slither and slime all over our precious plants and then consume leaves and petals,  without any consideration to the gardener.  They can’t even stick to the same leaf.  Nope.  They have to taste all of them.  Diatomaceous Earth is the answer.  It causes abrasions to insects when they come in contact with it.  The insects lose fluids and dehydrate.  It’s an organic control that works effectively.  Bonus – it also helps control earwigs, my arch nemesis in the garden.  natural guard

All of these things will reduce your gardening stress, as well as the stress on your plants.