By Claudette Sims, Halton Master Gardener
Clean tools
Take the time to clean your secateurs, pruners and saws before starting garden work. A simple wipe with rubbing alcohol between pruning plants will help to stop the transmission of disease. Learn more about caring for your tools on the Halton Master Gardeners’ website.
Perennials
Divide and transplant overgrown fall-blooming perennials on an overcast day before they fully emerge. Check this extensive spreadsheet of individual perennials for when and how to divide them. Add wire supports/stakes around tall perennials as they grow.
Veggies
Tomato seedlings can be transitioned to the garden slowly, starting with a sheltered location, from 1-2 hours on day 1, and increasing each day to full sun. Plant in the garden when they’re about 6” high (15 cm) when all danger of frost is past. Plant deeply, right up to the bottom leaves. Transplant tender seedlings like cucumbers, eggplant, and peppers once the soil has warmed up and the daytime temperatures are consistently above 18°C (65°F). Corn needs warm soil to germinate. Sow corn seeds when the oak leaves are the size of a squirrel’s ear.
Trees
Stop pruning oak trees to prevent deadly oak wilt disease. Inspect all trees for scale, fungus, or other disease. Add traps or barrier bands around trees to trap spongy moth caterpillars, which emerge from April to June.
Be a superhero! Choose native plants and remove invasive plants from your garden. Learn more at this webinar. Learn more at this webinar. My presentation starts at 15:30!
— Claudette Sims, Halton Master Gardener
Lawn
Early to mid-May is a great time to revive your lawn, especially if it is looking thin and weak. Over-seed, especially in thin areas, and then top dress with a ½ inch (2 cm) layer of fine-textured compost/manure. Choose a grass seed or mixture that suits your light conditions. Areas with moss may indicate soil has been compacted and the nutrient level is likely low. Consider embracing the moss and allowing it to grow, or transition that area to a non-invasive groundcover or garden bed with plants suited to the existing conditions.
Roses
Check this informative blog about caring for roses from the RBG. You can prune roses just as the new growth is showing. Here’s an introductory video (see below) to show you how. Consider adding some companion plants near your roses to attract beneficial insects, which will control pests: butterfly milkweed, dill, fennel, golden alexanders, “fireworks” goldenrod (Solidago rugosa), dotted mint.
Bulbs
Deadhead spent spring bulbs like tulips and daffodils, but leave foliage intact until it has died back. Tender bulbs like dahlias, gladiolus, and calla lilies can be safely added to your garden (or containers) after your last frost date. If you’ve started them indoors to get a jumpstart on growth, make sure to gradually bring them out for a few hours a day for several days to help get them acclimated before planting them in the ground.
