Mountain Garden Checklist: Summer Planting and Pest Management

Planting

• Butterfly plants: Nectar flowers—butterfly bush, butterfly weed, cosmos, gaillardia, marigold, rabbitbrush, potentilla, sunflower, verbena, zinnia. Fruit bowls for fruit-feeding species. Host plants for caterpillars—aspen, chokecherry, dill, fennel, hollyhock, ornamental grasses, parsley, sunflower. (Numbers usually small; call extension service to ID pests vs. beneficial caterpillars.)
• Container gardens: Replace spent cool-season annuals with heat-lovers: angelonia, bidens, bush strawflower, creeping zinnia, cuphea, floss flower, ground morning glory, marguerite, pimpernel hybrids, scaevola. Check soil twice daily; water when dry; fertilize weekly. Rotate pots; deadhead; cut back leggy stems by half.
• Gaps from dormant perennials: Spring bloomers (bleeding heart, fernleaf peony, spring vetchling, Oriental poppy, shooting star, Solomon's seal, Thermopsis) go dormant by midsummer. Cut yellowed foliage; plug in container annuals without disturbing roots.
• Madagascar periwinkle (Catharanthus roseus): Heat-proof, long-blooming replacement for annual phlox. Colors: lavender, peach, red, rose, white, most with contrasting eye. Trailing varieties (Carpet, Mediterranean series) for baskets/pots. Well-drained soil; allow to near-dry between waterings.

Maintenance

• Pest outbreaks: Blast aphids, juniper spittlebugs, spider mites, thrips with strong water stream (hit undersides). Spray susceptible plants (dahlias, phlox, roses) every few days for powdery mildew suppression.
• Weed killer damage: Avoid applying in hot/windy weather—chemicals volatilize, drift damages non-target plants. Follow label.