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

When: 3–8 weeks before the last spring frost.

• zones 3–5: about Mar 15 – Apr 19
• zones 6–7: about Feb 18 – Mar 25
• zones 8–10: about Dec 31 – Feb 4

Unpruned vines produce lots of small, poor-quality clusters. Heavy pruning balances the crop with the vine's strength.

1. Identify last year's canes: brown, smooth, pencil-thick, growing from the permanent arms (cordons).
2. SPUR PRUNING (most common): along each cordon, keep a cane every 6–8 in (15–20 cm) and cut it back to a 2-bud spur. Remove all other canes.
3. CANE PRUNING: keep 2–4 good canes of 10–15 buds each, tie them along the wire, and cut 2–4 renewal spurs of 2 buds each near the trunk.
4. Aim for roughly 40–60 buds per vine in total.
5. Remove dead wood, tendrils and old fruit mummies.

Tools: Bypass pruners, Loppers

Caution: Pruning cuts may 'bleed' sap in late winter. That's harmless.

When: 5–9 weeks after the last spring frost.

• zones 3–5: about Jun 14 – Jul 12
• zones 6–7: about May 20 – Jun 17
• zones 8–10: about Apr 1–29

Thinning shoots and removing leaves around clusters improves airflow and sun on the fruit, which means less rot and sweeter grapes.

1. Rub off extra shoots so they're about 3–4 in (8–10 cm) apart along the cordon.
2. After fruit set, remove the 2–4 leaves around each cluster on the morning-sun side.

When: 2–3 weeks after the last spring frost, then every 2 weeks (5 times a season).

• zones 3–5: about May 24–31
• zones 6–7: about Apr 29 – May 6
• zones 8–10: about Mar 11–18

Grape clusters are most vulnerable from bloom until about a month after.

1. Start when shoots are 1–3 in (3–8 cm) long. Repeat every 10–14 days before rain until 4 weeks after bloom.

What to use: 🌿 Wettable sulfur (e.g. Bonide Sulfur Plant Fungicide) · 🌿 Copper fungicide (e.g. Bonide Captain Jack's Liquid Copper) · Captan (fruit tree fungicide) · Myclobutanil (e.g. Spectracide Immunox)

Caution: Sulfur burns some American grape varieties (Concord and others). Check your variety first.

When: 14–18 weeks after the last spring frost.

• zones 3–5: about Aug 16 – Sep 13
• zones 6–7: about Jul 22 – Aug 19
• zones 8–10: about Jun 3 – Jul 1

Birds and wasps target ripening grapes.

1. Net the vine, or bag individual clusters in organza bags, as they begin to color (véraison).

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 black rot (remove every mummified berry) 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