May Garden Tips

“The world’s favorite season is the spring. All things seem possible in May.”

~ Edwin Way Teale

Echter’s Plant Doctors are available during store hours seven days a week to answer
your gardening questions. For accurate diagnosis, it helps to bring in a sample.

Flower Gardens

Wait until danger of frost has passed before planting tender plants. Frost blankets can help protect your plants from unexpected late freezes. When is it safe to plant my flowers?

Pinch back your annuals at planting to promote stronger, bushier plants and more flower production.

Annuals, vegetable plants and roses, selected from inside our greenhouses should be “hardened off” before planting outdoors. This is done by exposing the plants to the hot sun and drying winds gradually until the plants are fully acclimated. 

Use weed preventer to keep weeds from sprouting in your flower and vegetable gardens after you have set out your plants. Don’t use weed preventer where you are sowing seed until after it is up and growing. 

Summer-blooming bulbs like dahlias, gladioli, cannas and lilies can be planted outside now. If you started these bulbs inside and they are now up and growing, keep your frost blanket handy to cover them if there is a hard freeze predicted.

More on Planting and Caring for Annuals and Vegetables

Container Gardens

Plant your hanging baskets and container gardens now to give them a good head start. By June they should be well established.

Keep an eye on the weather and bring your baskets and containers inside if the weather gets cold. 

If your outdoor hanging baskets and planters have dried out too quickly in the past, mix granules of Soil Moist (a polymer) into the media of your container gardens and hanging baskets before you plant. This will help retain water for the plants to use as needed. We’ve added polymers to Echter’s Container Mix so you can reduce the frequency of watering.

Perennials & Roses

Prune back hybrid tea roses, floribundas and other everblooming roses to 10″ in early May. Also, prune out any dead, diseased or weak canes. 

Do not do a heavy pruning on climbing roses. Prune only those canes which are broken or dead. Deadhead, (cut off the old flowers) on daffodils, tulips, hyacinths and other spring-blooming bulbs, but don’t remove foliage until after it turns yellow. The foliage is making nutrients for the bulbs for next year’s show of color. 

Weeds take nutrients from the soil and away from your desirable plants. The smaller the weed, the easier it is to remove. Pulling them early will keep them from producing and spreading seeds.

Put up plant supports now for perennials that need to be staked, like delphiniums, peonies, yarrow, etc.  Before you know it these plants will be too tall to do it easily.

Speed up the warming of the soil in your perennial and bulb beds by removing the mulch from around the plants.

Vegetable Gardens

Before rototilling your garden, be sure the soil is on the dry side. Then, add compost and/or peat moss to the garden and work it all in. 

Make your list of the tomato varieties and pepper varieties you want to grow in your garden from these links. It’s easier if you know what you want before you go shopping.

  Echter’s Tomato Varieties        Echter’s Pepper Varieties

Plan your vegetable garden so that specific plants, like tomatoes, peppers, squash, cucumbers, etc. are planted in a different spot than they were planted last year. Rotation of your crops is very important to prevent any diseases prone to that particular vegetable. 

When planning your vegetable gardens, consider planting extra rows and donating the surplus to your local food bank. 

Plant your corn when the soil temperature reaches 60 degrees. Plant in blocks to improve pollination by the wind. Ross netting over your strawberries will help keep birds and squirrels out of your fruit crops. In addition, Bird Scare tape will be beneficial in protecting your fruit.

Check the “When is it safe…” link, which will enable you to judge when to plant your vegetable starts. For anything that you plant outside early this month, make sure that you have a frost blanket handy for those sudden and unexpected cold snaps. 

For fun try cherry tomatoes or strawberries in a hanging basket. Combine tomatoes with lettuce in a basket for color contrast in an edible combination. 

Cedar barrels or large pots make great vegetable gardens. Plant a tomato plant in the middle and lettuce, spinach or herbs around the edge for the beginnings of a great salad. Patio Prize tomato can be grown without a support. Indeterminate (vining) tomato plants need a tall tomato cage to support them. 

Plant your own cup of tea. Chamomile, lemon balm, catnip, spearmint and peppermint are just a few herbs that make delicious, healing teas. 

Never cut rhubarb stalks off the plant. Instead, hold the stalk near the base and give it a slight twist as you pull it away. Rhubarb flowers may be pretty, but they take away nutrients from the stalks. As soon as these flower stalks appear, prune them to the ground.

Bees are very important in pollinating fruit and vegetable crops. Time the use of insecticides before plants bloom and your will spare these beneficial pollinators. 

Lawn Care

Set your lawn mower blade to 2 ½ to 3″ to encourage deeper drought-resistant roots. The longer grass will keep the ground cooler and require less water. Mow your lawn during the day or early evening when the grass is dry. Never mow when there is moisture on the blades. This encourages the spread of disease and causes the clipping to clump. Leave your grass clippings on the lawn by using a mulching mower and reduce your need for fertilizer by 30 percent.

If you fed your lawn in April, put on another application of fertilizer before the summer heat arrives.
The best part of the day to water your lawn is early in the morning while it is still cool. There will be a lot less moisture lost to evaporation and the grass will be more resistant to fungal disease.

Now is a great time to reseed the bare spots in your lawn. Rake the areas thoroughly, scatter the grass seed and water it in, so that the seed can settle into the loose soil. Keep the seed moist until it has germinated. Fertilize with New Lawn Starter. Do not use a fertilizer with weed preventer in the areas where you have seeded or it will prevent the grass seed from germinating. If you had disease problems in your lawn last year, apply Ferti-lome F-Stop as a preventive measure

Echter’s Grass Seed Blends

Trees & Shrubs

Prune off old lilac flowers just below the flower right after they bloom. Trim out a couple of the thickest branches all the way to the base to help keep the lilac full and well shaped. Prune other early-flowering shrubs after their blooming time as well.

Watch for wasps or yellowjackets in and around your trees (especially aspens). This may be a sign that there are aphids on the leaves. By ridding your trees of the aphids, the yellowjackets will go away. 

Did you have worms in your apples last year? Help prevent these nuisances by spraying your apple trees with Bonide Fruit Tree Spray. Spray your fruit trees as soon as the flowers fade to control insects early. Another preventive measure is to rake up weekly all the apples which fall to the ground. 

Pines put out a thick shoot, (called a candle) from the end of the branch each spring. To control the height of mugo pines and have denser plants, use your fingers to break (do not cut) the candles in half before they turn green and the needles begin to separate. Do not remove the whole candle.

Spray plants with Bonide All Seasons Spray Oil to control oyster shell scale and other insects. This is a safe and effective insect control. If you had problems with mildew on your lilacs, a good spray of a preventive fungicide will help eliminate this problem. Read the label for the frequency of each spray.

Fertilize your trees and shrubs early in May. There are several ways to fertilize:
1) Use a Ross Root Feeder with the appropriate fertilizer pellet to get the solution right down
to the roots.
2) Use a topical granular around the plants and water in. 
3) Use slow-release fertilizer and work it into the soil around each plant. This feeds them for
several months. 

Water Gardening

Divide water lilies and other hardy pond plants this month. Place Aquatic Plant Tabs into the soil of your pots of water plants to fertilize them.

Water hyacinths and water lettuce are nature’s floating filters. They help oxygenate the water and keep algae growth down. Algae can also be controlled by a floating barley straw bale in the pond. 

May is a good time to introduce new fish to your pond. Float the bag that’s holding the new fish on your pond to equalize the temperature of the water inside to the temperature of the pond. Then release the fish into the pond. 

Wait to introduce the tropical water plants when the water temperature reaches and stabilizes at 70 degrees. 

Take your camera when visiting public gardens or even your friends’ gardens. If you want to have a beautiful flower or shrub you’ve seen, bring in a picture or a sample and we can help identify it for you.

Indoor Plants

Move your houseplants out to the covered patio at the end of May. Keep them out of the wind and direct sunlight. Remember to check them for dryness, since they will dry out much faster than they did indoors. 

Turn your houseplants a quarter turn periodically to keep the growth from leaning toward the window and the light. Fertilize your indoor plants twice a month with Jack’s Classic Houseplant Special. A good fertilizing program will help your houseplants get their good spurt of new growth this spring.


Plant a trumpet vine or honeysuckle to attract more hummingbirds. Stop by our customer service desk for a list of other plants which attract “hummers”.  

When trying to lure butterflies to your garden, place the butterfly-attracting plants in a large grouping.  A saucer full of wet sand will provide water for butterflies. Ask for a list of plants which will attract butterflies to your yard at our Plant Doctor desk. 

Attract ladybugs to your yard by planting marigolds, angelica, roses, butterfly weed, yarrow and many other plants. You can start your “colony” with ladybugs from Echter’s. Remember to disperse them in late evening when it is calm and mist the plant on which you need control first.


Check your hoses and connections to make sure they don’t leak. Echter’s carries hose repair kits and replacements for old washers. 

When you hand water, use a nozzle with a shut-off or trigger nozzle that stops the flow of water when released.