What to do in your Mountain garden in October
Plant Amaryllis bulbs in containers early this month for Thanksgiving bloom or late in the month for Christmas bloom. Choose a pot that's only 1 or 2 inches wider than the bulb. Plant the bulb, pointed end up, in commercial potting mix, leaving the top third of the bulb above the soil. Water once and do not water again until a green shoot appears. Place the pot in a warm, bright room and fertilize once a month. Tie tall bloom stalks to a stake to prevent them from falling over.
Set out drought-tolerant crocus bulbs now for color next spring. Crocus ancyrensis 'Golden Bunch' blooms as early as January in a hot, dry location. C. chrysanthus varieties are available in a range of colors, including lavender, purple, white, and yellow; they bloom right through February or March snows. Dutch crocus (C. vernus) bears blossoms 2 to 3 inches across in March. All crocuses perform best in well-drained soil in full sun. They naturalize well, increasing their numbers from year to year.
Hardneck garlic types like 'Bavarian Purple', 'Montana Giant', and 'Musik' are recommended for cold-winter climates. Separate "mother" bulbs into cloves; plant cloves individually, pointed end up, 3 to 4 inches deep and 4 to 6 inches apart. Spread mulch over planting beds. When green shoots emerge in spring, start watering weekly and fertilize every two weeks. Two good sources are Garden City Seeds and Territorial Seed Company.
At lower elevations, set out groundcovers, ornamental grasses, perennials, shrubs, and trees early in the month in Sunset climate zones 2b-3b. It's best to get plants in six weeks before the ground freezes.
Bring agapanthus inside. To keep container-grown agapanthus alive over winter, wait until after a light frost, then move plants into an unheated garage where the temperature stays around freezing. (Do not repot at this time; agapanthus bloom better when they're potbound.) Next spring put the potted plant outside in a sheltered area. Cut off the dead foliage, fertilize, and water whenever the soil dries out. When the leaves green up, move the plant to a sunny location.
When cleaning up containers, collect cuttings of coleus, Plectranthus, and Tradescantia to grow as houseplants for the winter. Remove the lower leaves from the stem, put the cutting in a colored-glass container of water, and place it on an east-facing windowsill. After roots appear, transplant the rooted cuttings to potting mix.
Blooming pots of chrysanthemums sold for fall color can be coaxed to come back next year. To increase their chances for survival, leave mums in the ground if you've planted them; if mums are in containers, transplant them to a flower bed that has good garden soil. Remove dead flowers, but don't cut the stems back. Surround the plant with several inches of loose mulch such as hay or pine needles. Water whenever soil dries out. Plants that survive the winter can be moved to a permanent location next spring.