June Gardening Tips for the Mountain West and High Plains
With pleasantly warm days and refreshingly cool nights, June is an ideal time in high altitude gardens. Use our checklist to keep your yard looking its best this month.
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If you live in a fire-prone area, check with your local fire department to learn how to landscape in ways that minimize damage during wildfires. Start by removing fuel sources near your home:
Trim branches that overhang structures.
Remove brush and dead vegetation on your property, especially near your home.
Keep plantings irrigated.
Move firewood piles away from buildings.
Clear gutters and roofs of plant material like dead leaves or pine needles.
Prune lower limbs of trees and remove small trees and shrubs beneath taller trees to eliminate fuel sources that enable flames to climb vegetation like a ladder.
Test Garden Tip: Maintain a fire-safe zone around your home that's a minimum of 30 feet (100+ feet on sloping sites). In this zone, space vegetation clumps 10 to 15 feet apart, separated by non-combustible materials.
Staying on top of weeds early in the growing season will make late season gardening easier.
If you're overwhelmed with weeds, focus your efforts by pulling or digging offenders about to set seed.
Spot spray weeds in lawns using a broadleaf herbicide that preserves turf grass while zapping weeds.
Dig or spot spray dandelions in lawns. Remember when digging dandelions that you need to get the top 2 inches of tap root to ensure the plant won't resprout.
For a homemade weed spray, mix 3 parts undiluted vinegar (10 percent acidity) to 1 part liquid dishwashing soap. Spray weeds. Tough perennial weeds may require repeated sprays.
Test Garden Tip: Create a targeted herbicide spray zone by cutting the bottom off a plastic gallon jug or by removing the top and bottom lids from a large trash can. Slip the bottom end of the jug or can over the weed and spray herbicide through the top, coating weed foliage.
Plant heat-craving vegetables such as beans, corn, eggplant, melons, peppers, and tomatoes. You can direct-sow seeds or use transplants.
Heat-loving herbs can go in the ground now: rosemary, basil, and lavender.
Add some perennials from the Plant Select program to your garden. These tried-and-true Rocky Mountain and high plains performers hail from a program by Denver Botanic Gardens and Colorado State University.
Colorado desert blue star (Amsonia jonesii) -- a western native with sapphire-blue blooms from April to early summer; fall foliage is yellow
Avalanche white sun daisy (Osteospermum 'Avalanche') -- white daisies all summer long above evergreen foliage; strong disease resistance
Grand Mesa Beardtongue (Penstemon mensarum) -- brilliant cobalt blue flower spikes in early spring last two months; evergreen leaves turn orange-red in winter
Test Garden Tip: When planting in June, water plants twice daily until they stop wilting. Even drought-tolerant plants need extra watering when first planted. Their drought-tolerant nature starts to show after root systems are established.
Snip off dead blooms from annuals and perennials. Removing faded blossoms encourages more flowers to form. Get flowering annuals on the fast track to a showstopping season by using bloom booster fertilizer.
Don't fertilize cool-season lawns during summer. Some grasses may go dormant during summer drought.
Feed tropical water lilies monthly through early fall to increase flower formation.
Continue fertilizing roses monthly to encourage more flowers to form.
Prune shrubs that have completed their bloom cycle.
Pinch the top inch of growth on garden mums near the end of the month.
Don't prune shrubs such as elderberries, viburnum, quince, cotoneaster, or currant after flowering unless you don't want fruit to form during summer.
Start slipping stakes into soil to keep flop-prone plants upright.
To avoid spearing dahlia tubers, add stakes at planting time.
Remove yellowed, brown bulb foliage as soon as it pulls free from soil without resistance. This process may take up to 6 to 8 weeks after flowers fade.
If tulip and hyacinth bulbs performed poorly this year, dig up and discard bulbs. How do you know when bulbs are kaput? They produce few or no flowers and spindly leaves and stalks. You can expect most tulips and hyacinths to last 2 to 3 years with a strong show. These bulbs typically dwindle in growth after that
Test Garden Tip: As this year's spring bulb blooms fade, plan where to plant bulbs in fall to enhance the show. Make a planting diagram or use marker flags to indicate where to add bulbs.