What to do in your garden in April
Planning and Planting
New plants. Among this year’s introductions are Agastache x ‘Ava’, a hummingbird mint with raspberry redblooms; Anthemis tinctora ‘Susanna Mitchell’, a creamy white daisywith lacy gray-green foliage; Aquilegia caerulea v. ochroleuca, a white-flowered form of Rocky Mountaincolumbine; Clematis scottii, a shrubby clematis with small, bell-shapedpurple blossoms; Lavandula angustifolia ‘Buena Vista’, a reblooming Englishlavender; scarlet-flowered Penstemon pinifolius ‘Nearly Red’; and Zauschneria ‘Mountain Flame’, which has scarlet-orangeblooms. All are winter-hardy in Sunset climate zones 2b-3b (Denver, Boise, Salt Lake City).Order from High Country Gardens (www.highcountrygardens.comor 800/925-9387).
Potted Easter lilies. When your Easter lily (Lilium longiflorum) finishes blooming indoors, you cantransplant it into the garden; it will often come back for severalyears, though blooming will shift to late summer. Plant the bulbs 6inches deep in good garden soil, then water and fertilizeregularly.
Time-tested perennials. In trials conducted by ColoradoState University, several perennials were standouts for the highplains of the Rocky Mountain region: Astrantia major ‘Margery Fish’ bears soft pink flowers inAugust; bear’s breech (Acanthus balcanicus) carries purple-and-white flowers inJune; Coreopsis verticillata is covered with small yellow daisiesfrom summer to frost; Heliopsis helianthoides scabra sends up yellow-orangedaisies in midsummer; Lavatera thuringiaca displays cup-shaped pink flowers on 2-to 4-foot-tall plants; Lysimachia ciliata ‘Purpurea’ has purple foliage and yellowflowers; and Sidalcea ‘Party Girl’ has pink flowers resembling tinyhollyhocks.
Attract beneficial wildlife. As frogs, toads, salamanders,and snakes emerge from hibernation, encourage them to stay in yourgarden and help control pests. Set shallow bowls or birdbath basinson the ground, and keep them filled with fresh water.
Cope with salt-laden soil. In parts of the intermountainWest, soils can have high levels of salts due to naturallyoccurring minerals, irrigation water, or fertilizers. Theconcentrated salts may show up as a powdery white crust on thesurface (a soil lab test can confirm the problem). One short-termfix is to flood the affected soil with water to flush the salts outof the root zone. The most natural solution is to plantsalt-tolerant flowers and shrubs. The list includes Apache plume (Fallugia paradoxa), artemisia, Colorado blue spruce,’Stella de Oro’ daylily, juniper, Jupiter’s beard (Centranthus ruber), lilac, mock orange (Philadelphus), saltbush (Atriplex species), Sedum ‘Autumn Joy’, and sulfur flower (Eriogonum umbellatum).
Spruce up birdhouses. Remove birdhouses from their perches,discard old nests, and wash out interiors with a bleach solution (4tablespoons of bleach to 1 gallon of water). Remount houses 6 to 20feet above the ground in a quiet part of the garden. If you don’thave a birdhouse, Audubon Workshop (www.audubonworkshop.com)offers a range of models.