Expert tips for growing daylilies

October 9, 2015

Daylilies are fairly trouble-free and the few problems they have are seldom serious. But there are ways to care for them over the years to ensure plants remain healthy and provide lots of blooms.

Expert tips for growing daylilies

How to water daylilies

In many parts of the country, natural rainfall will be enough to keep established daylilies growing well because of their deep root system.

  • Where summers are dry, watering will be needed if the plants are to produce blooms over a long period.
  • It is advisable to apply water by soaker hoses laid along the soil, or by watering systems that wind between the plants and have an individual emitter for each plant.
  • Where summers are hot, evening watering is preferable since less is lost by evaporation.

The right way to feed your plants

Feed new plants in spring the first year after planting, using an organic slow-release fertilizer (available from farm supply stores).

  • Apply a small handful around each plant and water with a diluted liquid manure tea a couple of times the first summer.
  • Once they are established, do not apply fertilizer as this will promote foliage at the expense of flowers. Instead, add a further layer of a mulch, such as well-rotted manure.
  • After a few years, if blooming is poor and few new growth fans are producing, feed in spring with an organic fertilizer at about half the recommended rate.

Getting rid of dangerous pests

Sometimes small insects gather in clusters on foliage and buds. If your leaves have become sticky and yellowish, you might have an insect infestation.

  • Aphids: If there are holes in your flowers and you notice insects hiding in flower throats by day, you are probably dealing with aphids. To get rid of them, try spraying your plant with a strong stream of water or apply insecticidal soap.
  • Earwigs: These are more of a nuisance unless numerous. Put out traps of short lengths of pipe, pots filled with straw, etc., and empty daily into containers of soapy water.
  • Beetles: If your foliage has a bronzy sheen and very fine webs on underside of leaves and on flower stems, you might have Japanese beetles (large), cucumber beetles (small) or a different beetle breed. Beetles often leave holes in leaves and flowers. Spray with neem, or try handpicking them if the infestation is small.
  • Spider mites: Almost invisible to the naked eye, their presence is only seen by their damage. They usually attack flowers, which will either fail to open properly or have small pale spots when they do open. To control them, try spraying your plants with insecticidal soap, especially on the undersides of the leaves.
  • Thrips: These are very small insects that feed on the developing buds by sucking their sap. They cause plants to wilt while the crowns become soft and smell bad. Control thrips by spraying your plant with insecticidal soap. It may be necessary to start spraying in spring, following a bad infestation the previous year.

How to recognize and remove common diseases

  •  Bacterial soft rot: If your healthy plant turns yellowish and stops growing or the leaves become twisted and crinkled, you might have bacterial soft rot. This disease is most common on sites with a high water table. Lift your plant immediately, scrape off all diseased material, soak in a 50% bleach solution for 10 minutes and replant in a different location.
  • Spring sickness: If white cottonlike threads appear in the crown, bearing small black fruiting bodies or your plant turns yellow, you might have spring sickness. The cause is unknown and some plant varieties are more prone than others. Plants generally recover when the weather warms up.
  • Mustard seed fungus also known as southern blight: This disease is more likely in warm climates. To treat it, spray your plant with Bordeaux mixture if slight. If serious, dig up plant, soak in Bordeaux mixture and replant in a different location.

Keep these tips in mind and cultivate healthy daylillies that will complement any outdoor space.

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