Candytuft: Easy-Growing Perennial Border Plants



The name candytuft elicits all sorts of cutesy references for me! When I first heard it, my mind immediately went to something straight out of a cartoon. I expected it to be vividly pink, maybe resembling cotton candy.

In reality, this decorative sub-shrub produces a dense flush of white flowers twice a year. And while my hopes of a Dr. Seussian-style plant may have been dashed, I do love candytuft nonetheless. It’s an easy grower, looks fantastic in borders, and consistently produces blooms.

Low-maintenance and relatively carefree, candytuft’s well worth a place in your garden. And truth be told, I’m happy it’s not cotton-candy pink. I like it just as it is!

So let’s explore the uses of this plant. From border edging to low-lying shrub, a mounding ground cover to a container-grown plant, there’s plenty of potential here.

Good Products For Candytuft Maintenance:

Overview

Perennial candytuft makes for a beautiful walkway plant. Source: juergen.mangelsdorf
Scientific Name: Iberis sempervirens
Common Name(s): Candytuft, evergreen candytuft, perennial candytuft
Family: Brassicaceae
Height & Spread: Up to 12″ tall, 24″ wide
Sun: Full sun best for flowering. Partial shade OK in zones 8-9.
Soil: Extremely well-draining, gravelly. Avoid hard clay.
Water: Drought-tolerant. 3/4″ to 1″ per week, but check soil first
Pests & Diseases: Very few pests. At risk of fungal root rot from overwatering.

All About Candytuft

The name “candytuft” derives not from candy, but from an city. Candia was the former name of Heraklion, the capital of the Greek island Crete. And it’s from that southern European region where it originates.

There’s nearly fifty species of plant that fall into the Iberis genus, but of these one’s very popular. Iberis sempervirens, the evergreen candytuft, produces vividly green foliage. And indeed, the term “sempervirens” means “always green”.

Other forms of Iberis are also referred to as candytuft. Yet this particular variety continues to be a garden staple. Its flowers, when they form in spring or fall, create a cloud-like mass atop the mounding plant.

There is at least one variation that lives up to the “candy” name. The “Pink Ice” cultivar of Iberis sempervirens produces pale pink flowers. Most others are all white with yellow centers.

Because of that mass of flowers, they’re excellent at drawing in pollinators. They also are somewhat drought-resistant, making them a good choice in low water uses. Their mounded foliage does not spread rapidly, but can be an effective ground cover.

As an edging plant, they excel. These make wonderful plants along sidewalks or porches. Their proliferation of foliage and flowers will tumble out of planters, too.

Plant Care

Closeup of candytuft flower
A closeup of a candytuft flower, showing its multiple layers. Source: audreyjm529

Iberis plants are easy to care for. These are very low-maintenance. Once established, they can recover well from adverse conditions. But let’s talk about the perfect growing conditions for this plant!

Light & Temperature

It’s generally said that candytuft survives well as a perennial in USDA zones 5-9. But there’s slightly different methods of growing it when the weather gets warm.

Gardeners in zones 5-7 should place their plants in full sun where they’ll get plenty of light. This tends to provide the best show of flowers. Those in zones 8-9 should opt for partial shade, primarily afternoon shade. As temperatures soar in summer, the shade gives them a break from the hottest part of the day.

The seeds need rather warm soil temps to germinate – 75 to 85 degrees is not uncommon. An established plant can tolerate higher ranges, although extra moisture may be necessary.

When the temperatures drop, especially in cold regions, a little protection helps. Gardeners in zone 5 should consider mulching at the plant’s base. Some choose to lay pine boughs over their plants in the winter to provide protection from icy winds.

Water & Humidity

In their natural climate, candytufts can be found in rocky, sandy regions. They’ve developed over time to really hate having wet feet. So it’s absolutely essential that you don’t overwater them!

For most plants, 3/4ths of an inch to an inch of water per week is fine. Water when the soil is dry in the top couple inches. This may be more frequent during the summertime. Younger plants will need more consistent watering as they become established.

Unfortunately, their natural environment tends to have drier air conditions. They may be tolerant of a lack of soil moisture, but they’re wimpy vs. humidity. Plants may wilt if the humidity rises. Because of this, they’re not recommended for the southeastern United States.

Soil

Gravelly or sandy soil is perfect for your plant, as it mimics their natural environment. Try to avoid clay-rich soils which lack drainage, because that can spell doom for the roots of your plant.

Soil with poor fertility isn’t that much of a challenge for the plant, nor is alkaline soil. In fact, perennial candytuft prefers slightly-alkaline soil. It can grow in neutral soil as well. Try to avoid acidic conditions.

Fertilizer

Provide fertilizer early in the spring for your plant. A slow-release balanced granular organic fertilizer is best. Work it into the soil in a ring around the plant’s base, trying to keep it directly above the roots.

During the growing season, you can provide a low-nitrogen, high-phosphorous fertilizer if needed. This will spur abundant flowering. But space out the fertilizing quite a bit. These plants often receive no fertilizer at all and still manage to grow well.

Propagation

Candytuft flowers
The white flowers of Iberis sempervirens blanket the plant in spring and fall. Source: TANAKA Juuyoh

Three methods are used to propagate this plant: seeds, cuttings, or root division.

Seeds take roughly two weeks to germinate. They won’t germinate unless the soil temperature is warm, between 75-85 degrees. It should also be moist enough to spur germination. When spring flowers fade, they will happily self-sow and new plants will appear in the summer.

Cuttings are a bit trickier. You should select green and healthy stems that are getting a bit long. They will self-root from leaf nodes along the stems, and can be air-layered. It takes a while for the roots to develop, so have patience with this method.

Root division is best done in the fall as it’s beginning to go dormant for the winter. Take care when dividing the plant to not break off the long stems. Ensure that you get both stems and roots in each clump, and don’t split it into small segments. One large plant can be divided into 2-3 smaller plants.

Pruning

These plants are fairly self-regulating in regards to their height. At a certain point, the stems will just bend back down to the ground. They will self-root if a leaf node is covered, enabling them to slowly spread. If you want to avoid spreading, trim longer stems with clean pruning snips.

After the flowers have faded in the fall, you can trim the plant back by a third to help regulate its size. This will also reduce the chance of the plant becoming leggy.

Sometimes legginess is desired, especially if these are planted in raised locations. The long stems will drape down along planters and retaining walls. If you’re trying for that effect, don’t prune and you’ll find it happens naturally!

Candytuft As A Ground Cover

I’ve mentioned a couple times that perennial candytuft can be used as a ground cover plant. If you’re looking to do this, plant individual plants about 6″ apart. If you’re in zones 5-7 and just barely into 8, full sun is perfect. In the hotter parts of 8 and 9, afternoon shade is desirable.

Make sure the soil is extremely well-draining. It’s best if the soil is sandy or gravelly before you begin. People with heavy clay soils will need to amend their soil to break up the clay at least 12″ deep.

As it begins to produce longer stems, use a fingertip to press areas with leaf nodes under the soil’s surface. This encourages those nodes to develop roots and form new plants to fill in.

A slow grower, it will take a while for your candytuft ground cover to fill in completely. Once it does, maintenance is effortless. Just appreciate the flush of white flowers twice a year and enjoy it.

This plant is not tolerant of heavy foot traffic. Avoid areas where people or pets frequent daily.

As an erosion-prevention cover, it’s phenomenal. I wouldn’t recommend it as a lawn replacement option. But if you’ve got a hillside you’d like to remain evergreen, this is a perfect choice. It sits close to the ground and will self-seed year after year.

Problems

You’re unlikely to experience major issues with this plant. Pests are almost nonexistent, and most of the diseases don’t cause severe harm. But here’s how to treat what few problems may arise!

Growing Problems and Diseases

Your largest risk factor while growing Iberis sempervirens is pythium-based root rot. Caused by too much moisture in the soil, this fungal root rot will cause your plants to yellow. Growth will be reduced, and if the moisture isn’t reduced your plant may die off. You may be able to carefully remove the plant from the soil and trim off damaged roots, then replant.

Leaf spotting is another relatively common issue. Largely caused by alternaria fungi or xanthomonas bacteria, these leaf spots are treatable.

Botrytis cinerea can also cause damage to the plant. These will cause fuzzy grey fungal spores on the leaves. Downy mildew will make a dusty grey powder form on leaves as well.

Of these disease issues, by far the worst will be the root rot. Most of the other diseases can be treated using a liquid copper fungicidal spray. For bacterial issues, you can use an organic fungicde that contains bacillus subtilis.

Pests

Most pests tend to leave your candytuft alone. Some stubborn aphids may appear if your area is prone to them, but they don’t cause much harm. Spider mites may occur in potted or planter-grown plants as well.

As a general rule, your plants are very unlikely to be subject to most pest attacks. In the rare occasion that they appear, treat according to the pest. Most respond well to the base practices for that pest type. Encouraging beneficial insects will handle most problems, though. Most of the time, the only control you’ll need is a little neem oil.

Wildlife like deer and rabbits do not find candytuft appealing. In part, this may be because the flowers don’t have a sweet scent. But regardless of reason, these are great in deer-proof or rabbit-proof gardening!

Frequently Asked Questions

Q. Do I have to worry about candytuft being invasive?

A. Generally speaking, no. While it does spread, it’s a very slow and manageable spread. You shouldn’t have to worry about it growing like a weed in your garden.

Q. Does Candytuft bear fruit?

A. Yes and no. It will produce a seed pod of sorts, but it’s inedible. Technically it is a fruit form, but it’s not what we consider to be “fruit”. You won’t find ornamental berries or other visually-appealing forms of fruiting here.

Q. Why are there spots appearing on my candytuft plant’s leaves?

A. Leaf spotting is usually a sign of one of two disease types. Alternaria fungi can cause spotting. So too can the bacteria known as Xanthomonas. Happily, both are treatable conditions!


I like to think of the candytuft in my garden as being a no-nonsense plant. You don’t have to fuss over it. There’s no specialized care required in most cases. And best of all, when it flowers, it REALLY flowers. Try pairing it with some catmint for a great springtime show!


The Green Thumbs Behind This Article:


Lorin Nielsen
Lifetime Gardener



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