Getting it to bloom

Why won't my Snow-in-Summer bloom? (and how to make it flower)

Also called Snow-in-Summer, Mouse-ear Chickweed (Cerastium tomentosum).

More about snow-in-summer

About Snow-in-Summer

Cerastium tomentosum · also called Snow-in-Summer, Mouse-ear Chickweed · flowering

A fast-spreading, silver-white-leaved ground cover in the family Caryophyllaceae, producing a dense carpet of white, five-petalled flowers in late spring and early summer. Its woolly, silver foliage makes it visually striking year-round. Extremely drought-tolerant and hardy, it suits rock gardens, slopes, and dry walls — but can become invasive if not managed.

Plant type: flowering

Watch for — Summer die-back in hot, humid climates: In humid regions with hot, wet summers, inner portions of the mat may die back. Trim back after flowering to open up the plant and improve airflow. Treat as a cool-season groundcover and expect some summer decline in USDA Zone 7+.

The reasons snow-in-summer isn't blooming

Almost every non-blooming snow-in-summer traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding snow-in-summer a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get snow-in-summer to flower

Maximise sun. Give snow-in-summer the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for snow-in-summer and get the feeding right with the snow-in-summer fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Snow-in-Summer flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full snow-in-summer care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Snow-in-Summer blooming — frequently asked questions

Why won't my snow-in-summer flower?

Snow-in-Summer blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make snow-in-summer bloom?

Give snow-in-summer the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does snow-in-summer normally bloom?