Selecting new flowers to plant this spring? Before falling in love with a colorful bloom, you’ll want to know if the maintenance requirements are a good fit for your garden. Which plants need cutting back after flowering? Which ones should be divided every year, or every 10 years, and so forth? Luckily Tracy DiSabato-Aust has the details you need to ensure you don’t bite off more than you can prune.
Mustard-yellow flower heads; fernlike, scented gray-green foliage
2–3 ft. (1 ft.) high; 3 ft. wide
Well-draining soil is the main element for survival. Usually trouble free if given full sun and well-draining soil; will tolerate dry soil. Normally does not need staking unless grown in excessively rich soil or too much shade. Divides easily in the spring or autumn, every 4–5 years. Relatively low-maintenance plant. One of the best yarrows for hot and humid conditions.
Light blue, white, or lavender flowers; small green leaves
10–15 in. high; 12 in. wide
Part shade–full shade
Plants prefer moist, humus-rich conditions. The foliage will die down if allowed to dry out in the summer or if given too much sun. Plants are shallow rooted and should be planted or divided in the spring to avoid the winter frost heaving that can occur with autumn planting.
Spiked flowers in various colors; palmately compound leaves
3–4 ft. high; 1 1/2–2 ft. wide
Full sun or part shade
A high-maintenance, short-lived perennial. Requires rich, high-organic, acidic, well-draining soil and cool summer temperatures for best performance. Provide afternoon shade in hot regions. Requires winter mulch in northern gardens. May require staking. Inoculating the roots with a legume inoculant before planting seems to improve performance. Divide by removing side shoots in the spring without lifting the whole plant. Yellow-flowered forms may be more tender. Cultivar ‘Candy Floss’ produces robust flower spikes, usually in shades of pink.
Daisylike flower heads in combinations of reds, yellows, and oranges; gray-green hairy leaves
2–3 ft. (1 ft.) high; 2 ft. wide
Often short-lived, usually due to wet overwintering conditions rather than cold temperatures. Well-draining soil, particularly over the winter, is vital to survival. Drought, heat, and salt tolerant. Avoid overly rich soil. Tall-growing forms require staking. Divide in the early spring every 2–3 years to maintain vigor.
Blue, purple, or white flower spikes; palmately cut leaves
4–6 ft. high; 1–2 ft. wide
Full sun–part shade
Delphinium elatum is the true “maintenance magnet.” It isn’t a beginner’s plant, although it seems to be one of the first perennials new gardeners are drawn to, perhaps because of the glorious pictures that appear in so many British references. It does prosper in England, due in part to the cool summers. This delphinium is prone to a host of diseases, and is a favorite food of slugs. It is also subject to crown rot in poorly drained soil and is short-lived. Carefully dividing plants annually in the spring may prolong life. Do not plant D. elatum too deep. It will require staking, and being a heavy feeder, it may need additional fertilizer in spring or summer. Many gardeners are better off treating this one as an annual.
Red funnel-shaped flowers; swordlike foliage
2–4 ft. high; 1–2 ft. wide
Hose off spider mites when they are first visible. Divide plants every 2–3 years in the autumn to keep vigorous, or separate offsets from the mother plant in the spring as growth starts. Crocosmia prefers moist, well-draining, rich organic soil. It can be short-lived in zone 5; planting in a protected spot and mulching can improve overwintering success.
Tracy DiSabato-Aust has earned international acclaim as one of America’s most entertaining and knowledgeable garden writers and professional speakers. She has extensive experience in the United States and abroad with more than 35 years in the industry and is a gifted and award-winning designer who combines artistic vision with practical horticultural strategies.
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