How to deadhead phlox?

How to Deadhead Phlox

Flower phlox image by Ivan chudakov from

Phlox is a vintage plant that can grow tall, or low as a functional groundcover. These perennial beauties may bloom for as many as six continuous weeks. While some varieties begin their flowering cycles in mid-summer, others may not begin until late in August. To ensure the plant’s overall health as well as profuse quality blooming for future seasons, it’s important to deadhead your phlox regularly. Removing spent blooms will distract your plant’s focus away from reproducing via seeds and direct its energies toward blooming.

Use clean, sharp shears to cut blooming stems freely from your phlox for indoor arrangements throughout the summer.

Clip off clusters of uncut flowers as soon as they’re spent throughout the season. Make your cut slightly above the first developing bud below the dead bloom.

Prune spent bloom stems down to ground level if new buds aren’t present. This will keep your plant looking tidy.

Trim phlox plants back as needed throughout the summer before a new flush of growth. Prune groundcovers regularly to keep them from become overgrown.

Cut the phlox plant to the ground when it has completed the blooming season. This will prevent undesirable reseeding. It will also allow the phlox to renew its resources and vitalize itself for a more vigorous coming spring.

Deadheading Summer Phlox

Deadheading summer phlox (Phlox paniculata) is a good example of how even within the same species plants can behave very differently, and our treatment of them might need to vary as well. In mid-August the plants that came into flower in July are beginning to either slow down or go by, so clipping the old flowers off can improve the appearance of the plant. For some varieties of phlox it can stimulate new flower production, but not for all. Here are some examples.

To deadhead phlox you clip just below the declining flower or seed heads.

This is a phlox called ‘Blue Paradise’ – it’s an interesting plant because in the early morning the flowers are very purple-blue, but when the sun hits them they turn pink.

Although the plant is cleaned up a bit after ‘Blue Paradise’ is deadheaded, it doesn’t usually produce side shoots and more flowers. As long as the foliage is attractive I leave it in the garden but when the leaves decline more from the leaf-spot that’s brewing, I’ll just go ahead and cut the plant down to the ground. So this is a Phlox paniculata that won’t flower again when deadheaded.

The phlox in the Volcano series from Tesselaar Plants put out strong new growth if they are deadheaded promptly. Even in a bad mildew year, when this plant does get some powdery mildew, this Volcano Pink With White Eye produces clean new growth that will produce a good new head of flowers.

Here is a Volcano Purple With White Eye Phlox that has been deadheaded about two weeks ago. You can see that this plant is already growing new leaves and buds. In late August this plant puts on a huge new show of flowers. In my gardens the Volcano Phlox are best at repeat flowering after deadheading.

This is an unknown phlox (Lavender David?) in the garden by my shed. It is reliably mildew-free every year and I clip the individual flowers as they go by rather than waiting for the entire plant to need deadheading. Sometimes I use this plant for cutting flowers as well. This plant produces some side shoots that bloom in response to deadheading, and the foliage remains attractive even if the amount of secondary bloom isn’t as prolific as it is on the Volcano series. So in general this plant is an asset in the garden even after peak bloom.

Just with the four varieties of summer phlox shown you can see tremendous variations in how the plants respond to deadheading. One of the pleasures of gardening with perennials is getting to know the plants as individuals.

When it comes to varieties there will be no shortage of choice, and flower colour varies from pure white through pale and dark pinks to salmony orange, maroon and purple. Choose one which suits your border’s colour scheme and, if you can, mass the plants for the most spectacular effect.

Plant your border phloxes 18in apart and they will soon fatten up over the next year or two so that little ground is showing between them. I grow several rows on my veg patch simply for cutting and they are great mixed in a vase with other border flowers.

When you want to make more plants the clumps can be divided – in autumn on lighter soils and in sheltered gardens; in spring where soil is heavier and the plants would have to sit in cold, claggy earth throughout the winter.

So if your borders are looking a bit peaky now – having given their all in May and June – keep them going with phlox. Unlike Herdwicks and Swaledales they won’t eat you out of house and home.

Don’t miss Alan’s gardening column today and every day in the Daily Express. For more information on his range of gardening products, visit

Providing Winter Care for a Phlox

A phlox plant can be a beautiful addition to any garden. If you want to keep this plant healthy during the long winter months, so that it comes back vibrantly in the spring and summer, it’s important to provide winter care for the plant.

So what are some things you can do to keep the phlox plant healthy in the winter?


For an outdoor plant, it’s important to add all lot of mulch to provide the plant with insulation in the colder months. This will keep the plant roots warm enough to survive until the spring and summer. You don’t want the plant to die in the cold weather.

Another method for maintaining and caring for the phlox plant in the winter is to cut back the leaves. This will help the plant survive the winter and come back with full blooms in the spring.


This is a beautiful plant that grows to different heights depending on the cultivar. It can grow from 15 to 48 inches with most varieties growing 24 to 36 inches tall. When it meets maturity, garden phlox creates beautiful clumps in your garden about 24 to 48 inches wide.

This plant does well in moderately fertile, well-drained soil. It does not like areas with poor drainage or soil that is always wet. It also prefers full sun but you can plant it under partial shade and it will still do well. In fact, this plant does well in the South where it can receive a good amount of afternoon shade.


These plants are very easy to grow and don’t require lot of maintenance. One thing you should do is remove flower heads when they have died. In addition, taller varieties may require support from cages or staking so that the flower clusters don’t get clumped together. Also, sometimes this plant gets a powdery mildew on the leaves. To avoid this, thin or divide the large clumps every few years to improve air circulation around the plants.

You can use phlox plants to accent your garden or provide a pleasant aroma. This flower also keeps deer away from your garden.

There are many different varieties of phlox, so choosing just one for your garden can be difficult (although a lot of fun). When you visit a nursery or garden center, make sure you take the time needed to go through all the choices and find something that you will enjoy growing in your garden.

If you have basic gardening skills, it’s very easy to grow phlox, no matter what variety you select. Plant creeping phlox if you want to create a good amount of ground cover, for example.

Taller varieties are perfect if you want to add height to your garden, and like the look of flowering plants that rise above the flowerbed. In the end, it all comes down to personal preference and what you enjoy having in your garden.

Tips on How to Deadhead a Phlox

As a perennial, Phlox should be regularly deadheaded to ensure constant and beautiful blooms and growth. A long time favorite among gardeners, the Phlox is a ground covering plant that has adorned cottages and Victorian homes for several hundred years. It is one of those vintage plants that never loses its appeal. One of the keys to success with this hardy perennial is to have a regular routine of deadheading. Anyone who has a perennial is going to be familiar with this method of removing the dead blossoms and cutting back the plant in the fall for renewed, and reinvigorated growth in the spring. Here are a few tips to help you get started, or maybe learn something new, about deadheading.

Fall Activity, or Summer

One of the problems that perennials have is that they spend a lot of energy in forming seeds within the blossoms that they have. However, what gardeners want from their plants is to see more buds and blooms forming. This provides color and fragrance throughout the summer. Deadheading is one of those ways to keep the blooms coming.

Deadheading your Phlox is usually done in the fall. This is the time when the blooms are all gone and all that is left are the dead heads of the blossoms. Simply cut them off so the plant can get ready for the winter season. Do not let that stop you from doing it any other time, though. If you see that some of the blooms dying out during the summer, cut them off. This will let the Phlox produce more buds.

Do Not Cut Off Developing Buds

It is easy sometimes to get a little carried away and cut off too much. Sometimes the new flower buds are lopped off in the process. Take great care not to cut off any of the developing flower buds. Take your hand and follow along the dead flower top until you get to the developing bud. Cut the stem off just above the bud.

Cut Stem Off

A question that is often asked at nurseries, and in online forums, is how far down to cut off the stem. The best answer to that is to remove it if you are not sure. This is mostly for aesthetic purposes as the flower will not have the “decapitated” look. If you just leave the stem, then it will look quite out of place. Cut off the entire stem for a more pleasing look.

Pinch Off Heads

Pinching off heads is used to keep the flower from growing too large. Cutting back on the height of the flowers will keep the Phlox as a low ground cover that will look great as a border, or arbor accent.

Light Shearing Through The Summer

As the Phlox continues to grow, in addition to the deadheading, a light shearing will also help it to look its best. By cutting back some of the growth, you can keep the Phlox from getting too large, out of control, and have that unkempt look. This should be done as the new growth is starting.

This week’s checklist: dead-heading

• Dead-head hybrid tea and floribunda roses by snapping off the spent flower at the abscission layer – the natural break point on the stem, usually 1in to 2in (2.5cm to 5cm) below the flower. This will promote slightly earlier repeat flowering.

• Cut delphiniums back down to the ground as soon as they finish flowering. Feed them and they will produce a second flush.

• Even plants such as irises (apart from Iris foetidissima, grown for its colourful seed heads) can be dead-headed. These won’t provide a second flush of flowers but the plant will put its energy in to beefing up the rhizome for next year.

Potting on dormant bulbs

• Spring bulbs have died down by now but only remain dormant for a short while. Narcissus bulbs are the first to be re-potted, as they will be rooting as early as August. Fritillarias will need repotting in July or August and crocuses around September.

• Repotting is designed to split overcrowded bulbs. It needs to be done only every few years, depending on the vigour of the species. Bulbs in pots are planted closer together than if they were in the ground but overcrowding can lead to poor displays.

• The free-draining potting medium we use at Wisley is a mix of loam, leaf mould and grit in the ratio 3:2:3. You can use John Innes No3 instead of loam and coir instead of leaf mould.

• The bulbs are planted as required for display, about halfway down the pot, or at the same level as they were before. Water well from overhead to settle the compost, then place somewhere cool, light and airy. The earliest will show signs of life before Christmas.

• Some fritillaries produce small bulbils the size of rice grains around the parent bulb. Many fall off during the repotting process, but they can be treated as seeds if more stock is needed. You will have to be patient as they can easily take three or four years to reach flowering size.


• To get a harvest of good-sized, high-quality fruit check your trees once the June drop – the natural process by which they shed any fruitlets they cannot sustain – has finished. If after this and the earlier late frosts there are still too many, thin them out.

• Always start by removing damaged and badly shaped fruits. Look out for signs of scab and for sawfly holes. Pinching them off with your finger and thumb is usually best because it’s quicker and is less likely to spread disease. But do use secateurs if the spur is in danger of breaking.

• Leave one or two dessert apples and pears per cluster, about 4in to 6in (10cm to 15cm) apart. Remove the king fruit – the large one in the middle of a cluster – on dessert apples if there is one and leave two well-placed fruits either side. Thin cooking apples to leave one fruit every 6in to 9in (15cm to 23cm). Plums are thinned to 2in to 3in (5cm to 7.5cm) and small plums to 2in (5cm).

  • With thanks to the team at Wisley (01483 224234;

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