What to do in your Mountain garden in June
When the weather warms up, sow seeds of cosmos, morning glory, portulaca, sunflower, and zinnia. For instant color, set out nursery transplants of drought-tolerant amaranth, creeping zinnia (Sanvitalia procumbens), Dahlberg daisy (Thymophylla tenuiloba), gazania, Madagascar periwinkle, petunia, purslane (Portulaca oleracea), Salvia coccinea and S. greggii, scaevola, moss verbena (V. pulchella gracilior), and Zinnia angustifolia.
Choose vining edibles to maximize space. Train vining fruits and vegetables (including cantaloupes, cucumbers, gourds, pumpkins, runner and pole beans, and summer squash) onto an arbor, trellises, or wires attached to a fence or a low roof. As vines grow, tie them to the support. As an added benefit, the ripening fruit stays clean, dry, and out of reach of damaging slugs and other soil-dwelling pests.
Add color with blooming baskets hung from sturdy supports. Good plant choices for sunny spots include bacopa, calibrachoa, cuphea, lantana, Madagascar periwinkle, nolana, trailing petunia, and scaevola. For shade, opt for begonia, ‘Diamond Frost’ euphorbia, fuchsia, impatiens, plectranthus hybrids, and all types of succulents. Choose baskets lined with plastic to minimize watering.
Grow flashy vegetables. Many veggies are as colorful as they are tasty. Some of the best are crimson-leafed ‘Bull’s Blood’ beets; bell and chile peppers; yellow ‘Golden Lumen’ and ‘Roc d’ Or Yellow’, and purple ‘Royal Burgundy’ and ‘Royal Purple’ bush beans; lavender-flowered cardoon; eggplants; ‘Lacinato’, ‘Red Russian’, and ‘Red Ursa’ kales; leaf lettuces of all varieties; ‘Osaka Purple’, ‘Purple Wave’, and ‘Red Giant’ mustard greens; ruby orach; and ‘Golden’ and red ‘Rhubarb’ Swiss chard. Available from Seeds of Change.
Plant a tough barberry For a colorful, small-space shrub (up to 5 feet tall and 2 feet wide), try ‘Helmond Pillar’, a columnar barberry with dark burgundy foliage. Hazel Suedes of Meadow Acres Greenhouse and Nursery in Evansville, Wyoming, says, "This shrub stood up to 100-mph gusts in the winter." ‘Helmond Pillar’ has yellow flowers in spring followed by small red berries; it grows in any soil in sun to part shade.
Try winning plants. Each year, the Plant Select program (a collaboration of Colorado State University, Denver Botanic Gardens, and regional nurseries and landscaping industries) names a few outstanding plants that thrive in the mountain region.
Plant Thai basil and cilantro now, and you’ll have fresh herbs all summer and beyond. Both annuals love sun and ample water, and do well in pots. Start basil from seedlings; to prolong leaf production, pinch off flower spikes as they develop, or let them go to enjoy the purple blooms. Because cilantro germinates quickly, sow seeds directly in the container. Begin harvesting when plants reach 6 inches tall; if you live in the low desert, wait to sow until fall.
When insect pests threaten, releasing beneficial insects into your garden is an earth-friendly alternative to using chemical pesticides. Planet Natural offers different kinds of good bugs that seek and destroy damaging insects such as aphids and mites. The Garden Variety Pack includes five types of predatory insects. Kids get a kick out of releasing a bag of ladybugs.
Remove bulb foliage. After the flowers fade, the leaves of daffodils and tulips can start looking downright ratty. Six to eight weeks after bloom, you can remove the withered foliage without interfering with the bulbs' nutritional process.
Tie up vines with paper-coated wire twist ties from bagged produce you buy at the market. Carry some along whenever you go into the garden to tie up fast-growing vines like clematis, grapes, and honeysuckle. You can also buy rolls of plastic plant ties at garden centers.
Groom spring-blooming shrubs like beauty bush, broom (Cytisus spp. and Genista spp.), daphne, forsythia, honeysuckle, Kerria japonica, lilac, mock orange, ninebark, roses, spirea, weigela, and white forsythia (Abeliophyllum distichum) after they finish flowering: Cut off seed heads and twiggy growth at the end of branches. Don’t prune barberry, chokecherry, cotoneaster, currant, dogwood, elderberry, quince, sand cherry, serviceberry, or viburnum, unless you want to stop them from producing fruit or berries.