May – June Gardening Task List
- If you started seeds last month, thin them and start the hardening-off process.
- Cut back spent Tulip and Daffodil blooms, but not the foliage!
- Divide and replant crowded Daffodils.
- Feed your roses and new plantings with slow-release fertilizer sparingly.
- Provide supports for fast-growing perennials such as delphiniums, peonies, and lilies.
- Tie up clematis and other fast-growing climbing vines.
- Hose off aphids, white flies, or spider mites on your roses or other perennials.
- Deadhead spent blooms on your annuals and perennials to encourage re-flowering.
- Water your newly planted shrubs, trees, and perennials.
- Weed regularly.
- Go on a local house and garden tour to see what plants are thriving in other area home gardens.
- Pinch back mums, salvias, and other late-season bloomers to encourage bushy, not leggy, growth.
- Check pots and containers daily for water needs.
- Plant dahilas, gladioli, caladiums, and cannas.
- Direct-sow annual flower seeds.
- Thin vegetable seeds sown directly in the garden.
- Move your houseplants outdoors for a summer vacation on your porch.
- Put out slug traps around your vulnerable edibles and hostas.
- Prune back forsythia, spirea, and other early-spring blooming shrubs.
- Check for black spot on your roses – remove and discard any affected leaves in the trash, never back into your garden or in your compost – and apply a fungicide with Neem oil every two weeks during the growing season.
- Cut some flowers to enjoy inside – make a small arrangement for every room.
- Sow squash and melon seeds.
- Plant seedlings or direct-sow sweet potatoes, tomatoes, peppers, and eggplants.
- Fertilize azaleas and rhododendrons, if needed.
- Divide crowded perennials and share them.
- Turn your compost pile.
- Start a water garden or renew yours for the season.
- Mark and photograph your bulb plantings now, while they are still visible.
- Keep a sharp eye out for fungal diseases and pests.
- Replace cool-season annuals with heat-loving ones.
- Be vigilant for mosquito breeding spots – any standing water, from a bottle-cap to blocked gutters – and clean them out immediately. Ask your surrounding neighbors to do the same. Put Mosquito Dunks in any areas that accumulate water.
- Plant tomatoes and peppers. To start them off rightm put cages/stakes in at same time as you plant them, so you do not disturb their roots later. Place a collar (cardboard tube or cat-food can) around the tender plants to prevent cut worms. Put crushed eggshells first in the planting hole of tomatoes for extra calcium and mix lime in the soil you surround the plant with to prevent blossom-end rot. Fertilize with kelp extract or fish emulsion.
- Hand-pick cabbage worms from cabbage and broccoli.
- Some of these may be a little late for most of you – as the weather varies, a number of you quite possibly are beyond the stage where you have any remaining bulb blooms (let alone spent ones).
The rain should let up soon (looking like we’ll see sun and warmth this week!), so this is truly a great time to transition your gardens!
This task list comes from the May 2016 edition of the Washington Gardener Magazine.