realenglishfruit

Top fruit tree growing advice and information from Real English Fruit

Tag Archives: frost protection

Video: An insect hotel and fruit tree pollination

Dan Neuteboom shows us an insect hotel. The problem with the pollination of early-flowering fruit trees, such as cherries, plums, greengages, apricots and peaches, is that often it is so cold, there are hardly any insects around. But when the sun does come out in those early months, it can quickly get very warm and the insects will come out. In this sort of insect hotel, which should be placed facing south, insects like hoverflies and lacewings can spend the winter. These are the insects that can help with pollination after just a few hours of sunshine. Dan shows us an open-centre greengage tree in which there is good air circulation. The basic requirements for good fruit set, in a location where there are other varieties all around, are there. The other important thing is that frost is a real danger with early-flowering fruit. The trees least at risk from spring frosts are apple trees. All the other trees flower earlier. There are various ways of avoiding the risk of frost and stopping the trees from getting hurt by frost. One technique is shown right here: the chickens keep the grass cropped right down, so that the sun can heat up the ground which can then radiate the heat back into the air at night, helping protect the trees from frost. Another useful technique is to use nets, ensuring that air circulation is not obstructed. Mulch also requires care. It is great for late-flowering fruits such as raspberries and apples, but if you put mulch around the trees early in the season, thinking particularly of frost-sensitive trees such as pears, peaches and apricots, you have to bear in mind that the mulch worsens the frost situation because it doesn’t allow the ground to absorb heat from the sun during the day. Lastly, the position of the trees should be considered when planting new trees. If you plant them in a valley where cold air can accumulate, this increases the risk of frost damage. In this case it can be useful to ensure that there is an opening in a hedge so that cold air can flow away.

Video: Apricot tree frost damage protection

Apricot and peach trees flower quite early in the season, even in March or early April. At that time of year there are a lot of night frosts which could cause apricot tree frost damage compromising the crop. Dan presents Carol Wilson, who has constructed a neat solution to the need of protecting apricot tree blossoms when there are night frosts. This specimen is a Golden Glow apricot planted in February 2017, so it is now about two and a half years old. It has been planted against a south-facing wall, and it has been carefully trained, so that all the leaves have excellent exposure to light. When it was planted, Carol ensured that there were no tree roots at the site, and removed all grass in the immediate area. She improved the soil with chicken pellets put into the hole. She made a frame that provides protection from muntjac and roe deer. Putting the frame up also gave Carol the chance to install a rail at the top, a piece of plastic tubing, that holds some garden fleece, hemmed as if it were a curtain. So each night, Carol closes the curtains to provide protection, and it is so easy that she can do it anyway, even if she is not certain whether or not there will be a frost. Dan provides some indications on apricot tree care and how to continue the apricot espalier training pattern. The success of this tree is shown by the abundant fruit already present in the tree’s third year. Dan also comments on apricot pruning – it is important not to cut out the thin wood, because the fruits are found on the one-year-old wood. This also applies to peaches.

The effects of weather on fruit trees, April-May 2017

This year, April and May have been very problematic weather-wise for anyone who is interested in home-grown fruit. On several nights, temperatures dropped to well below freezing. This has affected all the different types of fruit, inflicting moderate to severe frost damage to open blossom. Crop prospects are definitely a lot better on those trees which were covered with a double layer of garden fleece. Because of the tendency to flower earlier in the season, pears, peaches, nectarines and plums are all very badly affected. Apples, which flower later, usually still set some sort of a crop. This year I am afraid that even apples will have been thinned out a lot, particularly in frost pockets. We will know by the end of May for sure about the initial set. By early July we will finally know what’s left; this after the June drop has further reduced the number of fruits. Who said growing fruit is easy?

What to do next? Watch this space.

Evidence of frost damage on leaves

Why the correct choice of fruit tree is paramount to success, part 2 – site

A pear planted with protection from a shed wall

A pear planted with protection from a shed wall

Open sites without any protection against strong winds may be OK in the South of England. However in the North of England and Scotland, where the temperatures are already lower and the winds even stronger, compared with the South, the tree may survive, but regular crops are unlikely to be achieved.

However it is amazing what can be done if some sort of shelter is available, such as planting along a south or east facing wall or behind a tall hedge or a row of trees acting as a windbreak, for the area where the fruit trees are planted. However leave enough room as a headland, as fruit trees do not like to grow in the shade of other taller trees, neither do they like being planted on top of live roots of already existing trees in the surrounding area.

It is of great importance that where winds can be strong, the trees are properly staked and well secured with an adjustable tie. The stakes need to be planted in an upright fashion and be 6 foot in length and round with a diameter of 2 inches.

Unless planted in a walled garden, the best rootstock for open sites is MM106.

Secondly, valleys collect cold air and often lead to spring frosts at the time fruit trees are in blossom. The prospects of a decent crop will be diminishing with every spring frost in the period from late March to the end of May. For that reason try to plant further up the slope, where the air is warmer.

If there is a hedge or a dense row of trees that stops the cold air from draining away, a 3 to 4 metre gap should be created at the lowest point in the hedge.

Summarizing, fruit trees do best if planted at a site with a good micro climate of relative warmth and shelter. Valleys collect cold air and are therefore risky sites for fruit trees. This is linked to the possibility of serious frost damage to fruit tree blossoms in the period from April to May.

Why the correct choice of fruit tree is paramount to success, part 1

Apricot growing in the UK

Early Moorpark

Early Moorpark

We have a fine Apricot in our garden, and we have achieved excellent results. Here is a summary of what we have learned over the years.

It’s easy to grow. It has to be on a South-facing wall; it will need a space of approx. 6 to 7 metres wall length (this length can be shorter, but in this case, more summer pruning is necessary.) The planting hole needs to be thoroughly prepared. Use John Innes tree planting compost and make sure the tree is not exposed to a leak in the a gutter.

It’s important to provide thermal protection for the tree from mid February to the end of May. Fix large-size shelf brackets to the wall above the apricot tree and construct a wooden shelf. Use this to fasten a double layer of fleece each year around the second week of February. Cover the entire tree, and make sure the wind cannot blow it off at any time. Lift the fleece during the day only, when the tree is in flower, sp that pollinating insects can carry out their work. All this is necessary because the Apricot is very sensitive to frost. In addition, until leaf starts to develop, it is sensitive to “peach leaf curl” and bacterial canker. The great thing about apricot growing is that you do not need to use any chemicals, if you protect the tree as outlined above.

While the tree loves organic matter around its base, it’s important to keep it away from the trunk. It hates the grass around its base, so mulch the tree well, in order to keep grass and weeds at bay. Never let the tree struggle for moisture, and thin the young fruitlets when the size of a large pea, spacing them to at least 4 to 5 inches apart. Pick the fruit when turning yellow in August. At this stage, flavour will have developed well.

An apricot should never be pruned during the winter months, but always when there is a full canopy of leaves.

 

 

Tree development:

February/March of the first year:
Start with 2 side branches. Cut these back by about 2 inches. Remove all other growth (March). Promote strong growth by ensuring that there is sufficient water, nutrients and warmth (using the fleece as detailed above). Seal all fresh pruning cuts with “Heal and Seal” compound. This protects against bacterial canker.

Late September of the first year:
Select 2 shoots on either side. Tie in with bamboo canes at 45 degree angles. Cut the original side branches and the extra 4, back by about a third of their length. Continue to feed well (slow release fertiliser, Osmacote or the equivalent).

February/March of the second year:
Select the final 2 branches, and carry out the same procedure as in the first year.

From then onwards:
After cropping, cut out the wood that carried a crop (i.e. in August). Tie in new canes to replace the wood that carried fruit. Apricot crops best on younger wood. Never prune apricots during the winter months but ALWAYS as soon as you have picked the crop. This helps to avoid disease from developing. The same applies to plums, cherries, apricots, peach and nectarines.

Thinning:

Golden Glow, photo courtesy of coblands_plants/flickr.com

Golden Glow, photo courtesy of coblands_plants/flickr.com

It is important to remember that apricots tend to over-crop, and this leads to having too much crop one year and not enough the year after. To prevent this, you should observe the 1-year old wood of fully-grown healthy trees. If there is an abundance of blossom on this wood, then this wood needs to be cut back before the blossom has a chance to set fruit.

Secondly, once the size of the best young fruits has reached around 10mm, it is the right time to seriously reduce the number of fruits. Bring back bunches of fruitlets to singles and space the fruits 6 to 8 inches apart. Always retain the largest fruits. Continue to foliar feed the tree, and water the tree during the summer months. A shortage of moisture during the summer will affect the quality of the fruit buds the following year. If any summer pruning needs to be done later during the summer months, remove strong-growing surplus laterals. Do not cut out any new shoots which have closed down early. These usually carry the best fruit buds for the following year and therefore should be retained.

We can supply apricot varieties suitable for growing in the UK. Click here to go to the tree varieties page, where you can use the web form provided to ask for any additional information you may require with regard to your order.