Coreopsis plants are commonly known as Deathcap or Death’s Head. They are among the most poisonous plants in the world. These plants have been used in traditional Chinese medicine for centuries, but they were banned from use due to their toxicity. There is no doubt that these plants possess a strong narcotic effect, which makes them very popular with drug addicts and alcoholics alike.

The plant contains alkaloids such as N,N-dimethyltryptamine (DMT), 3,4-methylenedioxyamphetamine (MDA) and 5-methoxy-2-(pyrrolidinophenyl)-1-(3-fluoropentyl)-butanamide (PMBA). DMT is the main psychoactive component of the plant.

It causes hallucinations and altered states of consciousness. DMT is often referred to as “the spirit molecule” because it produces similar effects to those produced by hallucinogenic drugs like LSD and psilocybin mushrooms.

A number of different species of deathcap exist, including the common and highly toxic species: Coreopsis officinalis and Coreopsis sempervirens. Both species contain cyanide toxins, so they must not be handled around.

When and how to deadhead coreopsis plants

Deadheading is the process of removing spent flowers from annual and biennial plants. The main reasons why you should deadhead your plants are:

Improve the overall appearance of the plant. It prevents seedy or ratty looking growth on the plant, which might otherwise occur if certain branches aren’t regularly trimmed back.

Seedheads on many annuals and biennials can become large, heavy and unattractive. Removing these heads can keep the plant from being weighed down and help it stay attractive throughout the year.

It can encourage additional blooms, you just have to remember to deadhead your plants regularly if you want more flowers to keep appearing. Deadheading flowers also encourages additional growth, such as in flax and lavender.

Coreopsis Deadheading Guide – Should You Deadhead Coreopsis Plants on

Deadheading can sometimes promote re-blooming in snowball trees and coral bushes, but not always. It also may prevent the plant from going to seed.

It’s less laborious than trimming away large quantities of growth, although many plants need their ends trimmed from time to time. The real benefit of deadheading seems to be in keeping a tidy appearance, rather than for encouraging additional flowers.

When do coreopsis come back?

The simple answer to this question is that it will flower throughout the summer. If you live in an area that does not experience a hard frost coreopsis plants should flower until killed by frost. It is believed that coreopsis can survive light frost. You can help your plant survive a light frost by covering it with a sheet, blanket or other material before the frost hits.

What attracts hummingbirds to coreopsis?

As with many flowers, the color red tends to attract hummingbirds. Though it is also important to note that the shape of the flower is just as important. These two factors combined are a winning combination for attracting hummingbirds to your garden.

Are there any pests or diseases that commonly attack coreopsis plants?

The main insect pest that is likely to attack coreopsis is the aphid. These little creatures love feeding on the sap in the leaves and stems of the plant. If the infestation is bad this can result in leaf drop and plant death. You can treat for aphids with an insecticidal soap.

If you suffer from a lot of aphid problems, then you may want to purchase some ladybugs to place around your garden to help get rid of them. Though it is best to release them when there are no leaves on the plants, so early spring or late autumn is the best time to do this.

If you do not have ladybugs available you can also try rubbing the aphids off by hand or try spraying them with a strong jet of water in the morning. This will kill many of them and significantly reduce their numbers, making it easier for your plants to fight off the attack.

If the leaves begin to curl and turn brown during the summer then you should check to see if you have an aphid infestation.

Other than aphids, coreopsis are relatively free from pests and diseases.

How and when should I water coreopsis plants?

Coreopsis are relatively drought tolerant plants and only require watering during prolonged dry spells. If you notice the leaves starting to curl and wilt, this is usually an indicator that the plant needs water. This wilting is the result of the plants storing enzymes that are released when the plant starts to dry out. These enzymes break down certain proteins within the plant cells.

This is a self-defense mechanism that allows the plant to survive long periods of drought. If you notice this wilting occurring on your plants, you should wait for a few days of normal rainfall before you water the plants again.

This will allow the soil to absorb most of the water that is available and help the plants survive the drought situation. This wilting process is temporary and the leaves will re-green when the plant has access to water again.

What type of fertilizer should I use for coreopsis plants?

During the growing season, coreopsis will benefit from a balanced 10-10-10 fertilizer that you can apply to the soil. If there are no signs of growth, such as buds beginning to form, then you should hold off applying fertilizer for another week.

You can choose to apply the fertilizer at up to half the recommended strength to reduce the likelihood of burning the plants. If you notice curling or scorched looking leaves after you apply the fertilizer, then you should withhold fertilizing for another week before trying again.

To be effective, you should apply the fertilizer every few weeks during the growing season. How frequently you need to fertilize will depend on how much natural light your plants receive and which type of plant it is.

If you can, measure the sunlight that your plants receive and then search for the plant type and ambient light level on the fertilizer package to determine how frequently you should apply it. You should also apply more fertilizer during the summer when there are more hours of sunlight available.

What type of pruning is required for coreopsis plants?

Unless you are growing a specific type of coreopsis for its blooms, such as the ‘Zagreb’ or ‘Longitude’ types, then you will want to prune your plants to keep them full and compact. This can be done at the beginning of the growing season or just as new growth begins in spring.

Sources & references used in this article:

Taylor’s guide to growing North America’s favorite plants: proven perennials, annuals, flowering trees, shrubs, & vines for every garden by B Ellis – 2000 –

The Well-tended Perennial Garden: The Essential Guide to Planting and Pruning Techniques by T DiSabato-Aust – 2017 –

Deer in My Garden: Vol. 1: Perennials & Subshrubs by T DiSabato-Aust – 2006 – Timber Press

Evaluations of Floral Resources and a Horticulture Practice on Wild Bee Foraging in Urban Habitats by C Singer – 2006 –

Carolinas Gardener’s Handbook: All You Need to Know to Plan, Plant & Maintain a Carolinas Garden by NA Bjorklund – 2020 –

Annual and Perennial Flower Selections for North Dakota by T Bost, B Polomski – 2012 –



Comments are closed