Are Daylilies Invasive?
Are your daylilies taking over your garden? Are you worried they could be invasive? Invasive species harm pollinators and the local ecosystem. In this article, gardening expert Jill Drago discusses the invasiveness of daylilies and what you can do about it!
Invasive plants are exotic species that spread vigorously and interfere with the health of local ecosystems. They spread to wild areas via seed or rapidly growing root systems, crowding out native plants that provide essential resources for local pollinators and soil organisms. Aggressive and invasive plants negatively impact wildlife and the food web that depends on native species.
Daylilies are perennials famed for their beautiful flowers and simple maintenance requirements. As these plants grow, you may notice plant pups popping up nearby. Does this mean that your plant is invasive?
If you have an expanding daylily garden on your hands, let’s look at these plants, what may make them invasive or not, and what we can do about it!
Black-Eyed Susan Seeds
Blackberry Lily Seeds
Asclepius tuberosa Seeds
The Short Answer
The short answer is that not all daylilies are invasive. However, Hemerocallis fulva, commonly known as the ditch lily or tiger daylily, is invasive. You can still go to the garden center and choose your favorite beautiful daylily variety without worry. Most, if not all, of the popular hybridized varieties are not invasive.
The Long Answer
Hemerocallis fulva is a tricky plant. It is a listed invasive species in much of the US, but some gardeners consider it a lovely naturalizing plant that does not get too out of control. I inherited a patch of Hemerocallis fulva in my garden, and it has naturalized nicely. It’s low maintenance and has not negatively affected anything growing nearby. However, this may be a different situation where you live.
If you are worried that your orange daylily has become invasive, read on, and let’s tackle that issue!
The Orange Daylily Vs. Hybridized Daylilies
If you have ever driven down a road and noticed a lovely swath of orange daylilies filling a ditch, you have seen the orange daylily. This daylily goes by many different names. Hemerocallis fulva spreads aggressively, especially in perfect conditions. For this daylily, that means moist areas such as riversides or ditches where rain may collect.
The orange daylily produces seeds. However, those seeds are sterile and will not produce new plants. Instead, these perennials spread through their tuberous roots.
Hybridized daylilies may be aggressive. However, it is much easier to control the spread of these plants. Hybridized daylilies spread via seed. If you deadhead spent blossoms from your plants, you will not need to worry about daylilies taking over your garden.
How to Prevent
The easiest way to prevent your daylilies from spreading out of control is to avoid planting them if they have been declared invasive in your area.
However, if you love the look of the orange daylily, you can always grow this perennial in a container to keep it in check.
- Situate your container in full sun.
- Use any type of garden or potting soil as long as it is well-draining. Daylilies are not picky about their soil type, just as long as it does not hold onto water for too long, causing the roots to rot.
- Overwinter your potted daylilies by moving the container into your shed, or according to the University of Washington, leave your pots outdoors and cover the soil with a thick layer of mulch.
How to Remove Daylilies
There are a few different methods for removing daylilies. No matter what method you choose, try your best to remove every bit of those tuberous roots.
- Try removing daylilies with a good old shovel. This takes time and some elbow grease. It is important to remove as much of the roots as possible. Any remaining roots produce new plants next year, and the problem is only lessened but not eradicated.
- Try to mow or weed-wack the foliage of your daylilies all season long. Cover the area with a few inches of mulch or landscape fabric over the winter.
- As a last resort, use a systemic herbicide. Systemic herbicides can kill anything nearby. Unless they are targeted, they are not plant-specific. These herbicides are also rough on the environment and should only be used as a last course of action.
Asclepias tuberosa (butterfly weed)
Butterfly weed still offers a pop of orange while bringing in all sorts of pollinators. Hardy in zones 3-9, butterfly weed grows to two feet tall. These plants are crucial to the survival of Monarch butterflies as they are a food source and larval host plant. This plant is toxic to pets, though, so plant it with care.
Iris domestica (Blackberry Lily)
Do not let the name of this plant confuse you: it is technically an Iris. Hardy in zones 5-10, the blackberry lily grows to three feet tall. The sprays of flowers bloom in shades of red, orange, or yellow. Like the daylily, these blossoms only last about a day. On the other hand, this plant produces flowers for weeks, keeping blooms much longer than your traditional daylily.
Iris fulva (copper iris)
If you love the look of the orange daylily but not its invasive nature, the copper iris is a great look-alike plant. Hardy in zones 6-9, this perennial grows to three feet tall. The copper iris is a great option if you have standing water in your yard. This perennial produces copper-colored flowers that resemble lilies, along with lance foliage.
Lilium canadense (Canada Lily)
If you love the look of lilies in your garden, Canada lily is a lovely option. Hardy from zones 3-8, the Canada lily grows to five feet tall, which is a height that daylilies will not reach. The flowers on this perennial are yellow, orange, or red, typically with spots on the 4-inch petals.
Lilium philadelphicum (wood lily)
The wood lily is very popular, and it is easy to see why. Hardy in zones 4-7, this lily grows to three feet tall. Unlike the daylily, these lilies bloom for up to five weeks. The flowers are upward-facing and in a vibrant shade of red-orange.
Rudbeckia hirta (black-eyed susan)
The gorgeous black-eyed Susans may not give you the same look as a daylily, but they are dependable and low-maintenance perennials. Hardy in zones 3-9, Black-eyed Susans reach heights of up to three feet.
Their yellow-petaled flowers and their chocolate centers are classic garden perennials. Deadhead spent blossoms to encourage a second bloom and to keep this plant from spreading via seed.
Do not forget that not all daylilies are invasive. If you have your plant tags or are very familiar with the varieties you are growing in your garden, you will easily be able to do research. Most hybridized daylilies are clump-forming and are not invasive. Treat your orange daylilies as needed and remove them where they are problematic. If they appear contained, keep your eyes on them and monitor their spread.