Fertilizer
Candytufts are average feeders that require little additional fertilization when grown in moderately rich soil.
Perennials benefit from a one- to two-inch top dressing of compost, leafmold, manure, or worm castings in early spring.
Work it in gently over the root zone with a hand cultivator or hori hori garden knife.
Alternatively, feed perennials with a balanced or flower boosting fertilizer, using either a liquid or slow release application in early spring and again after flowering.
Balanced feeds have formulas with equal amounts of nitrogen, phosphorus, and potash, such as 5-5-5 NPK.
I like to use Burpee’s Enhanced All Purpose fertilizer.
Burpee Enhanced All Purpose Plant Food
You can find it available at Burpee.
Flower boosting formulas are slightly higher in phosphorus, like 4-6-2 NPK.
Down to Earth has a good product that you can find available at Arbico Organics.
Annuals can be fed in spring with the same balanced or flower boosting formulas about one month after planting and again in midsummer.
Cultivars to Select
Let’s have a look at some popular perennial rootstock and annual seed options.
Alexander’s White
Growing only six-to-eight inches tall, ‘Alexander’s White’ (I. sempervirens) is a charming, carpet-forming variety that’s covered in masses of scented white flower clusters all spring.
Hardy in Zones 3 to 8, plants in one-gallon containers are available at Nature Hills Nursery.
Forte
A showstopper with improved vigor and a long flowering time, Snowsurfer™ ‘Forte’ (I. sempervirens) features a dense display of fragrant white flowers that start blooming in early spring and last for weeks.
Hardy in Zones 4 to 9, plants in one-gallon containers are available at Nature Hills Nursery.
Rose Cardinal
Pretty and fragrant, the heirloom cultivar ‘Rose Cardinal’ (I. umbellata) is grown as an annual that gives clouds of rosy mauve flowers throughout the summer for an alluring groundcover or container plant.
Packets of seeds in a variety of sizes are available at Eden Brothers.
Maintenance
In fall after annuals have stopped flowering or been killed by frost, remove the plants from beds and containers and dispose of or toss them in the compost.
Perennials benefit from a light pruning in fall to maintain a compact habit and to encourage branching for more flowers.
Use clean, sharp shears to cut back plants by as much as one third.
If your garden is in the colder end of their hardiness range, Zones 3 and 4, an airy covering of evergreen boughs, burlap, or floating row cover fabric offers easy protection from desiccation if the snow cover is inadequate.
Propagation
Candytuft is easily propagated by division in spring or fall, stem cuttings in summer, and seeds in spring.
- To divide perennials, in spring or fall dig out plants in one piece.
- Use a clean, sharp spade to divide the rootball into equal pieces.
- Replant one section back into the original site and distribute the others as desired, planting into prepared, well-draining soil.
Stem cuttings from perennial plants are best taken in early to midsummer after flowering has finished.
- Use clean, sharp shears to take three-to-five-inch cuttings from healthy, nonflowering stems.
- Strip leaves from the bottom half of stems.
- Dip the stripped end into a rooting hormone if desired.
- Insert stems into cells or small pots filled with a moistened sterile starter soil mix.
- Place in a location with bright, indirect light.
- Keep the soil lightly moist until roots form in three to four weeks.
- Plant out when the temperatures cool at the end of summer or early fall.
If you collect your own seeds, use stock from species plants only – seed from cultivated varieties typically don’t grow true to the parent plant.
- Seeds can be direct sown after your last frost date.
- Sow seeds a quarter of an inch deep into prepared soil in a sunny, well-draining location.
- Water lightly and ensure the soil surface stays lightly moist for the best germination, which takes place in 10 to 20 days.
- Maintain lightly moist soil for the seedlings and when they have four to six leaves, thin to six to 12 inches between plants.
You can also use the thinned seedlings to transplant into other locations.
Pests and Disease
Candytuft is mostly an easy-care plant, but there are a few issues to watch for.
Caterpillars, slugs, and snails are the primary pests and these can be hand-picked and disposed of.
