Grapevine Calendar

January — Dormancy and getting ready to prune

What to do

• Clean and sharpen hand pruners, loppers and a small saw.
• Look over the vine: which canes are dark and sound, and which are dead or cold-damaged.
• On milder days without hard frost late in the month, you can start pruning.
• Check the trellis wires and posts — they are easy to repair now.

Why

Pruning is the most important job of the year. Preparing and looking the vine over first tells you how much to cut and which canes to keep.

Common mistakes

• Pruning in hard frost.
• Blunt tools that crush the wood.

Tip: Cut across a cane: green, living tissue means its buds are probably alive; brown means the cane has been killed by cold. After a hard freeze, also slice a few buds across: if many are brown, leave more buds when you prune.

February — Winter pruning

What to do

• Prune while dormant, before the buds swell, on days without hard frost.
• Remove around 90% of last year’s canes. An unpruned vine keeps hundreds of buds and gives many small, unripe clusters.
• Keep healthy, dark canes about pencil-thick with short spaces between buds — they are the most fruitful.
• Prune to suit the variety: to short spurs (usually 2–4 buds) or to one or two fruiting canes, each with a renewal spur of 1–2 buds.
• Remove dead and cold-damaged canes completely and take all prunings out of the vineyard.

Why

The number of buds you leave is the main way to regulate the crop — how many shoots and clusters you get also depends on how many buds are alive and fruitful. Too little pruning gives many poorly ripened clusters; too much gives heavy leaf growth and little fruit.

Common mistakes

• Pruning too lightly — the vine carries too many clusters.
• Spur pruning a variety that fruits further out along the cane.
• Leaving prunings under the vine.

Tip: If two canes are equally good, keep the one closer to the vine’s arm or head — it keeps the vine compact.

March — Finishing pruning and planting

What to do

• Finish pruning before the buds swell. Sap dripping from the cuts (“bleeding”) does no harm.
• If you hilled up the vines in autumn, pull the soil back once hard frosts are over — otherwise the grafted variety roots above the graft union.
• Tie arms and fruiting canes loosely to the wire; remove old ties that could cut into the bark.
• Plant new vines in early spring, as soon as the soil can be worked: full sun, well-drained soil.
• Plant at the depth the vine grew in the nursery; after planting, leave one strong cane with two buds.

Why

Pruning after bud swell injures the buds. New vines planted early have time to root before the heat.

Common mistakes

• Tight ties that girdle the bark.
• Planting in a low spot where frost and water collect.

April — Bud break

What to do

• Watch the forecast: young shoots are sensitive to late frost.
• On a first-year vine, let only the strongest shoot grow, tied upright to a stake; remove the others while they are short.
• Start checking the leaves once a week for spots and coatings.
• Do not overdo nitrogen — soft, lush growth is more prone to disease.

Why

The first weeks after bud break shape a young vine and show whether winter has damaged the buds.

Common mistakes

• Leaving every shoot on a young vine.
• Heavy feeding “for growth”.

May — Shoot thinning

What to do

• When the main shoots reach about 15 cm (6 in), thin them: keep the strongest shoot at each node and rub off weaker extras.
• Do not wait until shoots are long — by then it is easy to break off the wrong one.
• On young vines, remove the clusters if the vine is still weak, or keep one cluster per shoot.
• Guide shoots along the wires so the canopy does not become crowded.

Why

Thinned shoots give an open canopy, less disease and better-lit clusters.

Common mistakes

• Thinning too late.
• Leaving many clusters on a young vine.

June — Bloom, clusters and canopy

What to do

• Around bloom, remove clusters from short, weak shoots — a shoot needs roughly 90 cm (3 ft) of length to ripen a cluster.
• If the canopy is very dense and damp, remove a moderate 2–4 leaves around the clusters, only on the east (morning) side and only until the end of June, so the berries are not scorched.
• Check the leaves for yellowish oily spots (downy mildew) and white powdery coating (powdery mildew).
• Water deeply and infrequently in drought; keep water off the leaves.

Why

In hot summers, removing too many leaves scorches the clusters, but moderate opening of the canopy helps against disease.

Common mistakes

• Removing leaves on the sunny south or west side.
• Watering over the leaves.

Tip: Aim to see the clusters through the leaves like a chequerboard — dappled light, not full sun.

July — Berries swelling

What to do

• If the vine is heavily loaded, remove clusters on weak shoots before the grapes start to colour — this gives larger berries and earlier ripening.
• Trim overly long shoots, but do not shorten the ones you will choose fruiting canes from next year.
• Keep up the weekly check for downy and powdery mildew and grey mould; remove diseased clusters.
• Get bird netting ready.

Why

Thinning before colouring costs less crop and improves quality; thinning after it costs more.

Common mistakes

• Thinning after colouring.
• Cutting every shoot back hard.

August — Ripening and bird protection

What to do

• Net the vine or the fruiting zone — scare devices help only a little.
• Taste berries from the bottom of the cluster, because they ripen last.
• Watch for wasps on ripe berries and for split berries after rain.
• Pick early varieties when they taste sweet.

Why

Birds and wasps go for the grapes exactly when they ripen; netting is the only reliable protection.

Common mistakes

• Picking by colour alone.
• Netting after the birds have already found the vine.

September — Harvest

What to do

• Pick when the grapes are sweet, the cluster stem has turned brown and the seeds have darkened.
• Cut clusters with pruners on a cool, dry morning; do not pull them off.
• If rain is forecast and the grapes are ripe, pick them — rain on ripe fruit leads to splitting and rot.
• Store grapes in the refrigerator in a ventilated container; they keep for up to about three weeks.

Why

Grapes ripen only on the vine and do not ripen further after picking, while fruit left too long softens and rots.

Common mistakes

• Picking early because the grapes “have already coloured”.
• Storing them in a sealed plastic bag.

October — Late varieties and autumn clean-up

What to do

• Pick late varieties; once it turns cold, grapes no longer ripen.
• Gather fallen diseased leaves and rotting clusters and take them out of the vineyard.
• Note which canes cropped well and where disease appeared — you will need it when pruning.

Why

Diseased leaves and fruit left under the vine carry problems into the next season.

Common mistakes

• Leaving mummified clusters on the vine.

November — Leaf fall and rest

This month

What to do

• After leaf fall, clear around the vine and cut tall grass back from the trunk — rodents that gnaw bark shelter in it.
• In colder areas and on young vines (up to about 5 years), hill soil up around the base so the graft union is covered by about 8–10 cm (3–4 in) of soil — it stays much warmer under the soil than in the air.
• Do not prune in autumn — pruning belongs to late winter.
• Plan new vines and where they go: sun, good drainage, no frost pocket.

Why

Autumn pruning brings no benefit and exposes the vine to cold. A clear area around the trunk protects the bark over winter.

Common mistakes

• Pruning in autumn “to get it done”.

December — Season review

What to do

• Write down when bloom started and ended, when the grapes ripened and how much the vine produced.
• Note when and where downy mildew, powdery mildew or grey mould appeared.
• Get tools ready for pruning in late winter.

Why

Your own notes are the most accurate calendar — they show what really happens with your vine and climate.