Flowers: Hardy annuals are safe to plant now. Add long-blooming color with petunias, pansies, dianthus, and snapdragons. If you want to plant impatiens, geraniums, fuschias, and more tender annuals in the ground, wait til mid-month when you’re sure all frost danger has passed and night-time temps stay over 50 degrees.
All summer-flowering perennials, bulbs and shrubs are prime to get in the ground before the month’s end. Plant chrysanthemums for fall color.
Water: Conserving water with an irrigation system? Prep, prime and repair before things heat up this summer.
Vegetables: Tomato plants are flying off the shelves and we know you’re excited about crops of peppers, summer squash, melons, and eggplant. Wait until your soil warms up over 70 degrees before you move your starts from the greenhouse to the garden! Using a soil thermometer is a reliable and inexpensive way to protect your investment in fresh summer edibles.
Fertilizing: New shrub, tree, and rose plantings benefit from treatment with fertilizer (slow-release for roses and acidic type for azaleas and rhododendrons). Remember to water well after application. Not sure which type of fertilizer is right for you? Come down to the garden center and we can advise you.
Pruning: Azaleas, camellias and rhododendrons can be pruned back to eliminate frost-damaged branches in the last half of the month.
Lawn Care: De-thatch the lawn if old roots and stems at ground level exceed 1/2″ inch. Dig out perennial weeds, aerate, and overseed with grass mix if needed. Use a 3:1:2 ratio of natural, slow release fertilizer at a rate of 1 lb. of nitrogen per 1,000 sq.ft. during the last two weeks of May.
Pro tip: Set your mower blade height at 2” and leave the grass clippings where they fall. This mulch-mowing technique will feed your lawn with a natural source of slow-release nitrogen all summer.
Pests & Weeds: Get aggressive and eliminate weeds before they go to bud and seed. Herbicides will be much less effective then. Mulching is a great way conserve moisture and prevent weed seeds from germinating; you can use wood chips, shredded bark, or hay. Place mulch between and around plants from 2-4 inches deep for best results.
Put out bait or traps to keep slugs under control before they begin to reproduce. Clearing ground cover and mowing vegetation around your garden helps.
Is this list helpful? Check out the Thurston County Common Sense Garden Calendar for more.