Midsummer in Colorado means blooms, bugs and bursts of rain. Pay attention to all three, and your landscape should have a great rest of the summer.
Monsoon rain in our area from now until mid-August is caused by changes in wind patterns that bring in moisture from the Gulf of California and the Pacific Ocean.
Be ready for heavy rain or hail. Protect plants with shade cloth, sheets or floating row covers placed over plant cages. Large garbage cans or boxes work over pepper plants or patio tomatoes.
Perennials, shrubs and trees need special attention during summer heat. If you pick up sale perennials, wait to plant them until fall — or at least the cool of the evening or a cloudy day. Keep root ball moist for several days, but don’t overwater. Apply 3 to 4 inches of mulch.
No fruit on your tomatoes? They grow best with daytime temperatures between 70 and 85 degrees. Each tomato flower has about 50 hours to be pollinated or it will abort and drop (tomatoes are self-pollinated). Above 90 degrees, the plant focuses on survival, not fruit. Dry wind also causes blossoms to dry and drop. Secondary reasons for blossom drop include excessive or low nitrogen in the soil and low or too-high moisture. Shade cloth serves as a sun- and wind-break. Use chemical-free grass to mulch around plants; maintain deep, but infrequent watering.
Deadhead to promote more bloom. Daylilies, roses, geraniums, zinnias, coreopsis, marigolds and black-eyed susans appreciate regular grooming.
Leggy annuals reward a good pinching with more bloom and a flush of new growth. Pinch down a few inches into the stem to get a bushier, fuller and more attractive plant. Both annuals and perennials can be pinched back: petunias, zinnias, verbena, coleus, asters. Pinch mums now for the final time.
To prevent re-seeding, cut a plant’s seedpods off before they dry and release their seeds. If you don’t, snapdragons, garlic chives and cleome will gladly re-populate your landscape with new plants (some gardeners welcome these volunteers).
Many plants will bloom again with a mid-summer haircut. Use sharp scissors or shears; cut all the way down to where the leaves begin. Try this on salvia, lady’s mantle, catmint, sages.
Lavender won’t re-bloom after cutting. Use flowers and stems for crafting, potpourri or in the kitchen. More: www.ext.colostate.edu/ pubs/garden/07245.html
Disbudding, or removing side buds on certain plants before they bloom, will result in larger blooms. This works well for hybrid tea roses and dahlias and is usually done for flower shows. More: dahlias.net/dahwebpg/disbudding/disbud1.htm
This is a great time to shop for discounted annuals and perennials. Replace any ragged or almost dead annuals for continued summer enjoyment.
Fertilize container plants, but be careful not to use too much nitrogen, which produces more foliage growth than bloom. Use diluted soluble fertilizers with each watering, or go with full-strength weekly or bi-monthly. Be sure to read package instructions.
Before reaching for a spray, first identify the insect. Consult a Colorado State University extension volunteer or garden center. Or look it up using regional websites such as colostate.edu/Depts/CoopExt/4DMG/Pests/pests.htm. Check The Denver Post’s “5 garden pests” story if your maurauder is all too familiar: denverpost.com/grow
Many destructive insects will be taken care of when beneficial predators catch up to them. Spraying (even with less-toxic soaps) may disrupt this natural cycle. So get informed before you use them. Never spray on windy days or when bees or butterflies are flying or near ponds with fish.
Sap-feeding tomato and potato psyllids have arrived, at least in my garden. They lay small, orange-yellow eggs, visible to the naked eye, on the undersides of tomato, potato, pepper and eggplant leaves.
Adult psyllids inject toxic saliva into plants. You’ll first notice blotchy, brown-black areas on the mid-ribs and edges of tomato and potato leaves. Later, as leaves curl upward, they turn more yellow-green or purple-red. You know it’s psyllids when you see salt-like crystals, called lerps, over the plant. If you see lots of lerps, it may be too late to save the plant. Early scouting and early treatment are key.
Use preemptive controls if psyllids are a yearly problem: insecticidal soaps (spotty results), spinosad or horticulture oils. More: www.ext.colostate.edu/pubs/insect/05540.html
Spider mites thrive in hot, dry weather and feed on many plants, trees and evergreens. They cause bronzing discoloration, flecking and scorching of leaves, leaf loss and even plant death. Their webbing protects them and their eggs, keeping natural predators away. Pesticides will also kill spider-mite predators, and some products, like carbaryl (Sevin), boost spider mite populations. The best weapon: a strong blast of water from the hose. More: www.ext.colostate.edu/pubs/insect/05507.html
HELP FOR LAWNS
Our parched lawns and landscapes need attention. The Green Industries of Colorado, a.k.a. GreenCO, recently released four videos and five fact sheets to help homeowners during summer drought. Check them out: greenco.org/resources.html
More weeds than flowers? They are harder to pull or dig when the ground is dry. But leave them to flower and seed and you’re in for more weeds down the road. Spend a little time each day or week pulling or digging weeds, using spray as a last resort.