What to Do in the Garden in May

A Regional Gardening Almanac

Tips for Growing Bleeding Heart (Dicentra).
It's easy to see how Bleeding Heart got its common name. Photo: © Marie Iannotti

May is a frantic month in northern hemisphere gardens. Warm climates change rapidly to hot climates. Gardens in cold climates suddenly appear out of nowhere and demand attention. You may not need a list of what to do in the garden in May, because it is staring you in the face every time you walk through your garden. But here are some reminders of what you can do. Don't panic. The season is just beginning.


  • Treat yourself to at least 1 great new plant before the best selection is gone.


  • Water regularly, even if rain is predicted.


  • Deadhead spring blooming bulbs, but leave their foliage until it turns yellow.


  • Deadhead early spring flowers like pansies and primroses as the blossoms fade and begin replacing them in containers with warm weather bloomers.


  • Give everything a good feeding, to get things growing.


  • Divide crowded perennials and share.


  • Make sure tall perennials are staked.



  • Repot houseplants in new soil.

Trees & Shrubs

  • Check out spring flowering trees and shrubs while they are in bloom and make notes for future purchases.


  • Plant or transplant trees and shrubs before the heat of summer.


  • Start digging that pond you've been talking about.


  • Clean bird feeders.
  • Turn the compost


  • Keep a watch out for asparagus beetles, aphids, cabbage worms, cutworms, scale, slugs & snails and any signs of fungal diseases (leaf spot, mildew, rust...).


  • Rip out invasive plants while the soil is damp, before they spread even further.


Northern Gardens



  • Finish seeding annuals.


  • Resist the temptation to put out heat lovers until the end of the month, when night time temps remain above 50 degrees F.


  • Summer bulbs can be planted outdoors.


  • Plant new roses. Prune one-time blooming roses as they faded and feed.


  • Give fall bloomers like asters and mums, a first pinching back.

Trees & Shrubs

  • Plant or transplant trees and shrubs before the heat of summer.


  • Prune forsythia, viburnums and other spring blooming shrubs, before they set next year's buds.


Southern Gardens



Trees & Shrubs

  • Finish planting new citrus trees and berry bushes for a late harvest.


  • Prune flowering trees and shrubs as they finish blooming.


  • Clean up any drooping or ragged fronds on palm trees.


  • Keep a sharp eye out for fungal problems during the rainy season.

Southern Hemisphere

  • Make sure everything stays well watered.


  • Start putting the garden to bed by cleaning up spent plants and check for over wintering pests and eggs.


  • Continue planting trees and shrubs including conifers and fruit trees and plants.


  • Get spring bulbs planted.


  • Prepare the soil for winter planting. Check soil pH and add organic matter.


  • Consider planting a cover crop.


  • Bring the houseplants back into the house.


  • Start reviewing this year's successes and failures. Keep notes.

Gardening To Do Lists through the Year:

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