When to Plant Phlox?

When to plant phlox: everything you need to know

Phlox: a colorful classic in your garden

Phlox is a beloved plant among gardeners thanks to its long-lasting blooms and cheerful colors. You'll find them in all sorts of shades of purple, pink, red, white, and even blue. They also attract butterflies and bees, making your garden a vibrant place.

There are two main types of phlox: the low-growing creeping phlox (Phlox subulata) and the taller summer-flowering phlox (Phlox paniculata). The difference between these types determines when it's best to plant them in the ground or in a greenhouse.

The best time to plant phlox in open ground

The ideal time to plant phlox in the ground is spring or autumn. For creeping phlox, the best time is between March and April, just after the last frost. Spring is also suitable for summer phlox, from March to May, so they can establish well for summer flowering.

Ideally, choose a cloudy day or the day after a light rain shower to plant phlox. This reduces water evaporation and prevents the young roots from drying out. Ensure the soil is airy and well-draining, and consider using potting soil suitable for flowering plants, such as the potting soil mixes in our potting soil and accessories collection.

Planting Phlox in a Greenhouse: When and How?

Want to get a head start or beat the weather? You can also grow phlox in a greenhouse. Start in late February or early March, depending on the temperature in your greenhouse. Provide plenty of light, but avoid direct, hot midday sun.

Plant the young plants in cutting soil or humus-rich potting soil with adequate drainage. A good choice is a mixture with perlite or vermiculite to improve the soil's aeration. Once the plants are strong enough (4-5 true leaves), you can harden them off by placing them outside during the day and bringing them back in at night. From mid-April onwards, they can be moved outside permanently once the frost has passed.

Ensure the correct location

Phlox loves sun. So plant them in a spot that gets at least six hours of direct sunlight a day. Creeping phlox thrives in a rocky or sloping area where water drains easily. Summer phlox thrives in a sunny border, but also thrives in a raised bed or planter, as long as the soil doesn't remain soggy.

Although phlox loves the sun, it appreciates some afternoon shade during periods of extreme heat. Also, make sure it's placed in an airy spot, as this helps prevent diseases like powdery mildew.

When should you propagate or transplant phlox?

After a few years, you can divide phlox to rejuvenate or expand the plant. This is best done in spring (March/April) or autumn (September/October) after the growing season ends. Dig up the root ball, divide it by hand or with a garden fork, and replant a portion in a new location with fresh soil, possibly supplemented with pumice for drainage.

You can find more tips on transplanting in our comprehensive guide on when to transplant a plant .

Other plants that combine well with phlox

Colorful combinations for your border

Phlox looks stunning next to perennials like Echinacea , Astilbe , or Dahlias . They often bloom at the same time, but differ just enough in height and flower shape to create a playful ensemble.

Ornamental grasses or ground covers such as cat grass or Aglaonema also provide a beautiful backdrop for your phlox border, as long as there is plenty of sunlight.

Phlox as a herb gardening companion: original and practical

An unexpected but lovely combination? Place a few phlox plants near a herb garden . The flowers attract beneficial pollinators, which is good for your basil, mint, or chives. Be careful with competition for water, though; phlox is thirsty too.

Need extra help? We're here for you.

Have you planned phlox, but are you still unsure about the exact timing or care? Don't worry, we're happy to help. You'll find many more tips in our blog series on winter plant care and when to plant .

Or visit our store in Leuven and ask one of our plant pullers all your questions. We also have a beautiful selection of pots and other accessories that will give your phlox that little something extra.

Let phlox conquer your garden

Whether you want to transform a sunny border into a colorful spectacle, or let phlox creep over the edge of a window box like a soft mound of flowers, this plant rarely disappoints. Plant at the right time, give it some love (and water), and you'll be rewarded with a sea of blooms well into summer.

Want to stay up-to-date on more tips about garden plants and blooms? Then be sure to check out our other info blogs, such as those on when to plant dahlias or how and when to plant flower bulbs in flower boxes .

Have fun planting!