What to do when the cold sets in?
When autumn and winter set in, we protect ourselves from the cold by putting on warm pullovers and coats. Some plants need similar protection. This is how you can help them.
Protecting frost sensitive plants
Plants that are not winter-hardy (including all other plants that are liable to frost damage) should be given frost protection. When in autumn temperatures start to fall, and particularly when first frosts are forecast, start protecting perennials and shrubs. In spring when temperatures start to drop and/or night frost is forecast shelter all small and/or tender vegetables sown or planted directly outside.
Too late, were you? Now your plants may well suffer from frost damage and young, tender plants might even be killed in one go...
There are several ways to protect your plants:
- Cover frost sensitive plants with a layer of autumn leaves, straw or pine branches (for instance from your Christmas tree).
- Protect plants with fleece or jute. Both are breathable materials, preventing plants to get mouldy or even rot.
- Protect small and/or tender vegetables by covering them with glass or plastic cloches.
- Cover larger vegetables with a (low) polytunnel.
Plants in pots and planters
Protecting plants in pots and planters from frost is relatively easy. Bring them indoors (do so in time) and keep them in over winter, either on a cool spot or in the greenhouse. Wherever you put them, there should be enought light - evergreen plants need light in winter too, whereas decidious plants can cope with a darker spot. Please note: terracotta pots, when moist, may crack during frosty spells so prevent that happening by bringing them inside.
The Ice Saints represent a few days in May (11th-15th) when late night frosts still occur.So, you are well advised to wait until the middle of May before you bring any tender, frost sensitive plants or tub plants into the garden. The Catholic Ice Saints were St. Mamertus, St. Pancras, St. Servatius and St. Boniface, who celebrated their name days on May 11th, 12th, 13 and 14th respectively. But please remember: these Ice Saints offer no guarantee: always check the weather forecast as well.
Hardening off plants in spring
Hardening off is alowing plants sown and grown indoors to get used to outside temperatures. These plants tend be vulnerable, sometimes even weak, so you cannot just put them outside and hope for the best. They need a transition period from the comfortably warm circumstances they are used to to cooler ones. Start hardening off only after the Ice Saints have passed, when night frosts are far less likely to occur. Hardening off is a very gradual process: on day one, put your plants on a bright and sheltered spot, but not in direct sunshine, for about three to four hours; allow them an extra hour per day during the next five to seven days. After ten days or so they will be strong enough to remain overnight in the garden. Follow the same procedure with tubplants, allowing them some hours outside in a sheltered spot from the middle of April onwards, depending on the sort of plant and, as always, the weather.
To strengthen your plants further, why not use specific feeds such as ATA Terra Leaves. It'ss a complete plant feed, stimulating the development of strong shoots and side branches.
Do not prune in frosty weather
You're well advised not to prune in frosty weather. Frost may burst pruning wounds which will not heal quickly and are likely to leave scars. Evidently, pruning wounds form a source of possible infections. Also, do not prune when frost is forecast in the next three days, since wounds need to heal properly before they can withstand cold and frost.
To sow or not to sow?
If temperatures are still quite low, there's absolute no sense in sowing outside, as most seeds need warmth to germinate. However, you can start sowing a whole range of vegetables, flowers and herbs inside, from February or March onwards, depending on the plant or crop.