As autumn takes hold, the heating has been switched on and down here in the South East we needed to scrape the car windscreens two days running last month. I managed to find my gloves (both of them), which was amazing, but my scarf is still posted as missing and the snapped loyalty card means I have to buy a new scraper this weekend.
There's no doubt about it, the shorter days and dropping temperatures are a stark reminder of the impending winter. These changes - temperature, rainfall, wind, and day length - all have an impact on our plants. To get the best from our citrus fruit trees, late October/early November is the ideal time to prepare for what winter might throw at us!
After a successful citrus year - it's now time to harvest!
This year has been particularly good for citrus, with plenty of blossoms on the trees, favourable weather conditions for fruit set, and abundant insect activity to assist pollination. The extended growing season (thanks to a warm September) has allowed us to still see growth on all citrus plants.
The fruits are all ripening now and as usual, Liz is picking then as and when they ripen, preparing them for my beloved marmalade and then freezing them until the whole crop is ready for the best day of the year, Marmalade day!! Many of the lemons are cut into slices and frozen ready for the evening G&T. One frozen slice per glass is perfect and prevents watering down the 6.30pm reviver as the dreaded ice cubs do.
Protecting against frost
Whilst a long growing season is welcome, it also poses a problem. The latest growth is very green and with no lignification of the shoots occurring, this means it is most susceptible to frost damage.
It's pretty simple; the new green shoots are full of sap which freezes; the cells expand, and the cell structure breaks down. This means we lose all of that valuable extension growth. So, it's now time to plan for a little frost protection.
Option 1 - a greenhouse
Those of you with a cold greenhouse have the best facility. Lots of light and enough protection from the cold with the glass. If things look to be heading for a real “Beast from the East” situation, then additional covering of fleece or bubble plastic should cope with that. However, do try to make a tent over the tree so that the bubble or fleece is not touching the leaves and shoots.
Option 2 - a garage or shed
Next best is a garage or wooden shed. Usually there is limited sunlight in these two buildings, but for short periods the citrus plants will come to no harm. However, I urge you to bring the citrus out into the daylight just as soon as you are able, even if that means for just a few hours a day. That is also the case for the cosseted glass house plants. Let them have pure daylight when ever possible.
Option 3 - a plant tent
With a little effort, a small protective tent can easily be made and placed on the south or west side of a wall or hedge. This option offers great protection. Fleece is not really strong enough and plastic sheeting easily degrades or rips. Search out protective plant tents or suitable protective non rip fabric if you can - there are some excellent ones on the market. As with the extra protection in the glass house, do make sure that you prevent the tent covering from touching the leaves and shoots of the citrus plants. If there is heavy frost or freezing rain then the below freezing temperature will be directly transferred to the plant if the two surfaces are touching. Do email us with any examples of your constructions. we'd love to see them!
Option 4 - natural protections
Finally, there are natural protections. Placing the citrus against the wall of a house, especially a west or southerly aspect can give really good protection as I found out last year. It probably means that I have rubbish insulation, but it certainly worked.
Hedges and trees offer very good protection too. The best seems to be privet, yew and cypress trees. I know of two excellent gardens that place their citrus collections under Yew, Cypress and Privet and the plants over-winter marvellously well.
When to Take Protective Action?
So, when do we need to take all of this protective action? Well, citrus can accept short term, below freezing temperatures such as the ground frosts of mid October this year. But when the forecasters suggest that your area may see a sharp drop to -4ºC or lower, and there are also strong winds (which will drive the temperature well below this), then act quickly and remember the boy scout motto - Be Prepared!