Garden mum care guide: when & how to prune, fertilize and spray

When: 4–6 weeks after the last spring frost, then every 3 weeks (3 times a season).

• zones 3–5: about Jun 7–21
• zones 6–7: about May 13–27
• zones 8–10: about Mar 25 – Apr 8

Each pinch doubles the number of branches, and so the number of flowers.

1. When shoots are 6 in (15 cm) long, pinch off the top 1–2 in (3–5 cm) of each stem.
2. Repeat every 2–3 weeks. Stop by early July (about 12 weeks after last frost) or the flower buds won't form in time.

When: from 4 weeks before the last spring frost until the last spring frost.

• zones 3–5: about Apr 12 – May 10
• zones 6–7: about Mar 18 – Apr 15
• zones 8–10: about Jan 28 – Feb 25

Old mum stems shelter overwintering beneficial insects and protect the crown in winter. Cutting them in late winter clears the way for fresh growth.

1. Cut all of last year's dead stems down to the new growth at the base.
2. Do it before new shoots get tall, so you don't snip them by accident.
3. Leave the cut stems loosely on the ground or in a brush pile for a few weeks so emerging bees can escape, then compost them.

Tools: Bypass pruners or hedge shears

When: from the last spring frost to 3 weeks after.

• zones 3–5: about May 10–31
• zones 6–7: about Apr 15 – May 6
• zones 8–10: about Feb 25 – Mar 18

A single feeding as new shoots emerge is enough for most perennials. Overfeeding makes them floppy.

1. Scatter a balanced slow-release or organic fertilizer around the plant, or top-dress with 1 in (2–3 cm) of compost, then water.

What to use: 🌿 Balanced organic granular fertilizer (e.g. Espoma Plant-tone 5-3-3) · Slow-release balanced fertilizer (e.g. Osmocote Smart-Release 14-14-14)

When: 3–7 weeks after the first fall frost.

• zones 3–5: about Oct 22 – Nov 19

Prevents freeze–thaw cycles from heaving roots and protects the crowns through the coldest weeks.

1. Wait until the ground has frozen or had several hard frosts. Covering too early invites rodents.
2. Mound 6–10 in (15–25 cm) of shredded leaves, straw or compost over the crowns.
3. Pull the mound back gradually in spring once hard freezes are over.

What to use: 🌿 Clean straw (not hay, which carries seeds)