Blooming Garden Designs

Specializing in Natural and Sustainable Landscapes

May Gardening Tips

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Happy May- With the spring showers comes the beauty of the Midwest garden. Whats not to love: various shades of green as the backdrop to the spectacular natives and old-fashioned garden plants.  Want to make your garden shine all year… check out my Gardening Tips. If you are too busy to spend much time in the garden this month…check out the top three maintenance tips.  Guaranteed to help your garden look its best!!


When buying bedding plants, choose compact, bushy plants that have not begun to flower.

If you want to plant perennials (come back every year), plant tag must read:  hardy to  ZONE 5—if it is Zone 6 or higher treat as an annual ( it may not overwinter in Central Illinois).

CAUTION: Watch temperatures– our average last frost date is around Mother’s Day

        Dahlias, Gladiolas, tuberous Begonias, Lilies and Cannas and other summer flowering bulbs can be planted this month. Gladiolas bulbs may be planted at 2-week increments until the first of July to provide you with cut flowers until the first frost.

        Delphiniums, Phlox, Daylilies, Carnations, Aubrietia, Candytuft, Basket of Gold, Primroses, Coral Bells and Saxifraga and other summer flowering perennials may all be set into the garden any time in May.

        Petunias, Geraniums, Fuchsias and Impatiens should be ready to plant by mid-month. Toward the end of the month, it should be warm enough to plant out the more tender annuals like Salvia, Zinnias, Marigolds, Lobelia.

        Mums can be planted for fall color, will need to be pinched back until late July.


        Carrots, lettuce, potatoes, corn, beans, peas and most popular vegetables (with the exception of the warmer weather crops) can be seeded or planted into the vegetable garden at any time now.

        Wait until mid to late May before planting the warmer weather crops like tomatoes, squash, cucumber, pumpkins and peppers.

        With a little luck, you may begin to see the first fruit on your strawberries by late this month. The birds will enjoy them very much if you don’t provide some protective netting over them. Newly planted strawberries should have the blossoms picked off until they become well established.

        Gourds may be planted late in the month



Top 3 Tips

  1. The first flowers you’ll see will be your weeds. Work to eliminate the weeds (roots and all), before they have a chance to go to seed.
  2. It’s still not too late to fertilize your trees and shrubs. Use a ‘Rhododendron’ or an ‘Evergreen’ type of plant food to feed evergreens and acid loving plants like Rhododendrons, Camellias, Azaleas, and Junipers, etc. Use an all-purpose garden fertilizer (10-10-10) to feed roses, deciduous shrubs and trees. Be sure to water the fertilizer in thoroughly after it is applied.
  3. Lightly side dress perennials with an all-purpose 5-10-10 or 10-10-10 fertilizer. Avoid spilling the fertilizer on the plant, and use care not to damage the shallow roots when you cultivate it into the soil.

        Remove the wilting seed heads from Rhododendrons and Azaleas, so that the plants energy can go to foliage growth and next year’s flowers, rather than seeds.

        Work lime in the soil around your Hydrangeas to produce pink flowers or Aluminum Sulphate for blue.

        Remove any sucker growths from fruit trees as soon as they appear.

        Keep a vigilante eye on the roses. Keep them sprayed for aphids and other pests and diseases such as black spot.

        Pines and other conifers can be kept to a compact size by pinching off the new growth ‘candles’.

        Setting the stakes next to your taller flowers early in the season, will help to support the plant against winds as well as making it easier to ‘train’.

        Promptly remove spent flowers from any plant unless your intent is to harvest the seeds. It consumes the plants energy to produce the seeds, and in many species of plants (especially annuals), removing the dead flowers will promote further blooms


        With the spring showers comes the beauty of the Midwest garden. Early flowering deciduous shrubs such as Forsythias, Weigela, and Spiraea should be pruned back when they have finished blooming. Cut back a third of the oldest canes to ground level, then cut back one third of the remaining branches by one third of their height.

        Lilacs should be pruned lightly after they finish blooming, removing sucker growths and dead blooms. Feed lilacs in May with a good all purpose 10-10-10 fertilizers after they have finished blooming. If your soil has an acidic pH, work a little lime into the soil as well.

        Break off wilting Tulip or Daffodil heads but continue to feed and care for the plants until the foliage has died back naturally. Old plantings of Daffodils may be divided and moved when they have finished blooming, but treat them as growing plants and use care to protect the foliage and roots. Water them thoroughly after transplanting. It is best not to dig or move other spring flowering bulbs until their foliage has ripened and died back.


        May is a good month to repair your lawn. Fill in the bare spots by slightly loosening surface of the soil and sow a good quality lawn seed over the area evenly. Tamp the seed in gently and water. Keep the patch moist by covering with light mulch of lawn clippings.

        This is the time to eliminate lawn weeds by hand pulling, or the application of a ‘weed and feed’ fertilizer…. before they go to seed!.

        Setting your mower for a higher cut during the spring months will help the grass to grow in fuller and help choke out the weeds.


        Utilize your compost now in amending your soil. Constantly add fresh garden refuse to it. The compost pile should be kept damp. Frequent turning will turn your garden waste into flower food much faster. Recycle Reuse!

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