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

When: 2–8 weeks before the last spring frost.

• zones 3–5: about Mar 15 – Apr 26
• zones 6–7: about Feb 18 – Apr 1
• zones 8–10: about Dec 31 – Feb 11

Quince flowers at the tips of new shoots. Heavy heading cuts remove flowers, so thin lightly instead.

1. Remove dead, diseased and crossing branches, plus root suckers.
2. Keep an open, vase-like shape with 3–5 main branches.
3. Thin crowded interior shoots, cutting back to a side branch. Avoid shortening every shoot.
4. Cut out any shoots with leaf blight cankers or old fire blight damage.

Tools: Bypass pruners, Loppers

When: 5–8 weeks after the last spring frost.

• zones 3–5: about Jun 14 – Jul 5
• zones 6–7: about May 20 – Jun 10
• zones 8–10: about Apr 1–22

Trees set far more fruit than they can size up. Thinning gives bigger, better-tasting fruit, prevents broken branches and stops the tree alternating between heavy and empty years.

1. Wait until after the natural 'June drop', when fruit is about marble to walnut size.
2. Twist or snip off fruit so the survivors are spaced 6–8 in (15–20 cm), mostly to prevent branches breaking in heavy years apart along the branch.
3. Remove the smallest, damaged or misshapen fruit first.
4. It feels wasteful, but you'll harvest about the same weight of much better fruit.

When: from 2 weeks before to 2 weeks after the last spring frost.

• zones 3–5: about Apr 26 – May 24
• zones 6–7: about Apr 1–29
• zones 8–10: about Feb 11 – Mar 11

Quince needs very little fertilizer. Too much nitrogen means soft growth that fire blight loves.

1. Top-dress with compost, or apply a tree fertilizer at half the label rate.

What to use: 🌿 Finished compost or composted manure · 🌿 Organic tree & shrub food (e.g. Espoma Tree-tone 6-3-2)

When: 2–6 weeks before the last spring frost.

• zones 3–5: about Mar 29 – Apr 26
• zones 6–7: about Mar 4 – Apr 1
• zones 8–10: about Jan 14 – Feb 11

Kills overwintering spores of quince leaf blight and fire blight on bark and bud scales before they can infect new growth.

1. Spray on a dry day above 40°F/4°C, just before buds swell.
2. Cover all bark and buds thoroughly.
3. Rinse your sprayer well afterward. Copper corrodes metal parts.

What to use: 🌿 Copper fungicide (e.g. Bonide Captain Jack's Liquid Copper) · 🌿 Lime sulfur (e.g. Lime-Sulfur Spray)

When: 2–6 weeks after the last spring frost.

• zones 3–5: about May 24 – Jun 21
• zones 6–7: about Apr 29 – May 27
• zones 8–10: about Mar 11 – Apr 8

Mulch keeps roots cool and moist, suppresses weeds and slowly feeds the soil. Applying it after the soil warms lets roots wake up first.

1. Spread 2–3 in (5–7 cm) of mulch over the root zone.
2. Keep mulch 2–3 in (5–7 cm) away from stems and trunks. Mulch piled against bark invites rot and rodents.
3. Don't go deeper than 3 in (7 cm) in total. Too much mulch suffocates roots.

What to use: 🌿 Shredded hardwood or pine bark mulch

When: from 4 weeks before the first fall frost until the first fall frost.

• zones 3–5: about Sep 3 – Oct 1
• zones 6–7: about Sep 27 – Oct 25
• zones 8–10: about Nov 3 – Dec 1

Quince is ripe when fully golden and fragrant. It stays hard, and is picked before frost.

1. Pick when the skin turns from green to golden yellow, the fuzz rubs off easily, and the fruit smells strongly sweet.
2. Cut or twist gently. Quinces bruise easily even though they're hard.
3. Store in a cool place apart from other fruit, as the scent carries. Cook into jelly, paste or poached fruit.

When: from the first fall frost to 4 weeks after.

• zones 3–5: about Oct 1–29
• zones 6–7: about Oct 25 – Nov 22
• zones 8–10: about Dec 1–29

Spores of quince leaf blight overwinter on fallen leaves and splash back up in spring. Removing them is the single best way to prevent next year's outbreak.

1. Rake up and remove fallen leaves and dropped fruit from under the plant.
2. Bag diseased material or put it in the trash. Don't compost it unless your pile gets hot (140°F/60°C+).
3. Cut out any dead or obviously diseased twigs you can see.

Tools: Rake, Bypass pruners