To smooth the transition from pots to garden, add compost into the planting holes for your roses and clematis. Make planting holes at least twice as wide as the pot they came out of, then backfill halfway with a 50-50 blend of topsoil and compost. Reduce transplant shock by watering your newly planted roses and clematis with a transplant fertilizer. Vitamin B-1 is usually a key ingredient in these fertilizers. This vitamin activates plant disease resistance and causes plants to release rooting hormones, which results in strong root growth. Water new additions to the garden during the first season, providing 1 inch of water per week through rainfall or irrigation. Test Garden Tip: Give your plants an extra boost by topdressing the soil with compost in spring and again autumn. This is especially helpful for sandy or clay soils.
May Herb Gardening Tips for the Northwest
Tuck herbs into the garden as soil warms. Plant dill and fennel in vegetable gardens and flower borders for an airy texture. The blooms to attract beneficial insects, which can keep harmful insects in check. Allow plants to set seed and you’ll be rewarded with volunteers next year. Edge your planting beds with herbs. Chives, ‘Spicy Globe’ basil, tricolor sage, and parsley all make pretty edgings. Thyme forms a lovely ground-hugging mat that’s ideal for front-of-the-border planting. If your planting beds tend toward the moist side, tuck Mediterranean herbs – rosemary, thyme, and lavender – in unglazed terra-cotta containers. The porous pots keep roots on the dry side, so plants can thrive. Learn more about dill. Learn more about fennel. Learn more about chives. Learn more about basil. Learn more about tricolor sage. Learn more about parsley. Learn more about thyme. Learn more about rosemary. Learn more about lavender.
May Vegetable Gardening in the Northwest
Plant your favorite heat-loving veggies this month. They include eggplant, hot and sweet peppers, tomatoes, melons, squash, beans, corn, and cucumbers. Direct-sow seeds or plant seedlings – either will have your kitchen overflowing with great flavors later in summer. Get tomatoes off to a solid start by backfilling extra-deep planting holes with nutrient sources. To the bottom of the hole, add a fish head from a local seafood market – this is an organic way to provide nitrogen and calcium. Next add a handful of bonemeal and three to four crushed eggshells – both add calcium, which helps prevent blossom-end rot from being a problem later in the summer. Learn more about seed-starting.
Weeding
Keep after weeds while they’re small – they’re easier to pull and if you get them before they go to seed, you won’t have as many weeds to pull next year. Pull weeds after spring rains, and they’ll slip easily from soil than when the ground is dry. Deal with weeds in driveways or along paths with spot sprays of glyphosate – or for a more environmentally friendly solution, try boiling water. Vinegar kills young seedlings, but is ineffective on older growth. Vinegar damages any plant surface it touches. Use with caution on windy days. Test Garden Tip: Insert stakes for flop-prone perennials when plants are 6 inches high. Candidates include peony, heliopsis, summer garden phlox, or Shasta daisies. Plants will hide stakes as they grow.
Fertilizing
If you have poor soil, dig in some type of controlled-release organic fertilizer into planting holes this month for anything you plant. This is especially helpful for annuals and perennials. When direct sowing annuals or vegetables, you can work fertilizer into planting beds. Or wait until after plants are up and have been growing two weeks, then scratch fertilizer lightly into soil.
Planting
Tuck tender, summer-blooming bulbs, corms, and tubers into soil now as it warms. This includes cannas, dahlias, gladiolus, and summer-flowering lilies.
Test Garden Tip: Insert stakes for dahlias and other bulbs at planting time to avoid spearing tubers by staking after growth has started.
See more great summer bulbs.
Mowing season is here. Follow these tips to make the most of your mowing efforts.
Never remove more than one-third the length of grass blades at any cutting. Mow bluegrass to 2-3 inches; tall fescue to 2.5-3 inches.
With mulching mowers, feel free to let clippings remain on the lawn. They’ll return nutrients to soil as they decay. The exception is when grass is especially long or wet. Rake these clippings and toss them onto the compost pile.
As summer heats up, reduce irrigation to 1 inch of water every two weeks. Lawns will slip into dormancy, turning straw colored, but will revive and green when fall’s cooler air arrives.
