When should I take winter protection off my plants?

The autumn half of winter protection gets all the attention and the spring half causes at least as many losses. Growth under a wrap comes on early, in the dark, without wind — pale, soft and completely unprepared for the conditions it is uncovered into.

Step by step

1. Watch the plant, not the calendar.The signal is the plant starting into growth: shoots pushing through a mulch collar, buds swelling, pale new growth appearing inside a wrap. That happens weeks apart in different gardens and in different years.
2. Take mulch collars off first and earliest.As soon as shoots appear through the mulch, pull it back off the crown and spread it around the plant instead. Shoots growing up through a deep collar etiolate and rot at the base.
3. Ventilate wraps before you remove them.Open the top, loosen the ties, or roll a hessian sleeve down part way for a week or two first. This lets the tissue underneath firm up and gets it used to light and air gradually.
4. Uncover on a dull, still, mild day.Not a bright cold one. Soft growth exposed straight to sun and wind scorches within hours, and a clear day is also likely to be followed by a clear cold night.
5. Take the last layer off in the evening.Removing a cover in the evening gives the plant a whole night and the following morning's gentle light to adjust, rather than an immediate blast of midday sun.
6. Keep fleece to hand for a fortnight.You have just exposed the softest growth the plant will make all year, in the season when late frosts happen. This is the period when the protection you removed is most likely to be needed again for a night.
7. Check what has been living underneath.Deep straw and mulch collars shelter mice, voles and slugs all winter. Look at the crown and the base of the stems for chewing when you uncover, because damage found in March can still be worked around.
8. Clean and store what you removed.Dry fleece and hessian before folding. Mulch that is still in good condition can be spread as a surface dressing rather than binned.

Tips

• If in doubt, uncover the top and leave the base protected. The root zone can stay mulched for weeks longer with no downside, and it is the top growth that needs the light.
• Protection removed from a container plant should be followed by a check on the compost. A pot that has been wrapped all winter is often either bone dry or waterlogged, and both need dealing with before growth gets going.
• Plants that were wrapped tend to break into growth ahead of unwrapped ones nearby. That is not an advantage if the frost risk has not passed — it is exposure.
• Note the date you uncovered each plant and whether you got caught. Two or three years of that gives you a better rule than any general advice.

Common mistakes

• Leaving wraps on 'just to be safe' well into spring — Growth underneath comes up etiolated and weak, ventilation is poor so rot and mildew set in, and pests breed undisturbed. Late removal causes losses just as reliably as early removal does.
• Stripping everything off on the first warm bright day — The first warm bright day in spring is usually followed by a clear cold night, and soft growth that has just been exposed to full sun is at its most vulnerable.
• Removing protection and putting it away immediately — You will want it within the fortnight. Leave it folded by the back door until the frost risk period has genuinely passed.

Questions people ask