Toward the end of May, when your tulips and daffodils stop blooming, they need some care if you expect them to come back and bloom again in the years ahead. The goal is to maximize energy storage in the bulbs.
Try this approach:
- As the blooms fade, remove them. This "deadheading" will minimize the energy the plant wastes to produce new seed.
- Apply a balanced fertilizer as blooms fade. If you have a long bloom period, apply the fertilizer once you need to start deadheading early blooms. You don't have to wail until all blooms are finished, as the earlier bloomers may be fading by then. Use a fertilizer with roughly equal amounts of nitrogen, phosphorous and potassium.
- Do not cut back foliage until it turns brown. It generally takes about eight weeks after bloom for the foliage to fade. During that time, the leaves are manufacturing and storing carbohydrates in the bulb. Avoid the temptation to do anything with these leaves. Don't trim, braid or tie them. Just let them be until they die back.
- If you wish to remove and replant any bulbs, you can dig them up after the foliage dies back. You also can wait until autumn to dig them up and move them, but it is much easier to see where they are planted while the brown foliage is still in place. Dig carefully to avoid damaging the bulbs. Once they are out, gently brush off the soil and let them dry in a cool, dark, well-ventilated location.
It is important to dry them in a single layer. Once they are dry, examine them for any signs of disease or damage. Remove offsets - new bulbs that have formed on the parent bulb. They will be new plants next season. Discard any damaged bulbs. Continue storage until autumn, when you can replant them.
Daffodils can be maintained for many years using these practices. They are long-living perennials.
Tulips are less long-lived and somewhat more difficult to perennialize. Some tulips, such as Darwins and other varieties, are more likely to perennialize. If your goal is to have perennial tulips, choose your variety carefully and plant them in a place that will have fairly dry soil during their dormant period, as excess water will rot them.
Many people use tulips as annuals, digging up the bulbs after bloom and discarding them. The bulbs are relatively inexpensive, and this can work really well for gardeners who use a lot of summer annuals.
When you have questions, email ask.extension.org or call 520-7684 from 9 a.m. to noon Monday-Thursday. For garden tips, visit facebook.com/ColoradoMasterGardeners.EPC