Derry's Orchard & Nursery

Planting a potted fruit tree

If the tree is on M9 or Bud 9 rootstock, it will need a stake for the life of the tree (3" x 8' wooden fence post with 2' in the ground, or studded tee-post, or regular tee-post). If on M26, Quince, SJA, M7, MM106, MM111, Antonovka it will need a stake for a couple of months only.

Plant your tree as soon as possible.

Put the stake in first. Dig hole only as deep as the pot and
at least 2x width. Do not amend the soil. Form a mound of soil in the bottom of the hole.

Holding the rootstock portion of the tree, take the tree out of the pot, shake off all soil and/or potting mix. Straighten out the roots so they form a circle radiating around the trunk. Cut off any broken roots and any roots which will not radiate properly.

Place tree on top of the mound so the roots radiate evenly around the mound and all point downwards. Keep graft union as far above soil as it was in the pot. Backfill the hole with the native soil. Stake should be on the windward side of the tree and about 4" away from the trunk at soil level. Tie tree to the stake using an old stocking or a strip of rubber forming the tie into a figure of 8 so the tree will not bang against the stake when it is windy. Step on the soil to press it against the roots. Mulch with organic matter or the leftover soil from the pot or compost or leaf mulch (to retain water). Water tree well to settle it.

1) If it is Spring and if the tree is a whip (see photo of a whip under 'rootstocks') and you are going to grow it as a standard pyramid-shaped tree, cut it back to 30" if it is a weak variety or to 31-33" if it is a vigorous variety. If all goes well, the branches will form in the 6-8" below the cut. If it is Fall, do not cut back now, wait until Spring. Open cuts are vulnerable to diseases in our winter rainy season. Cut back in late February or early March just before the sap starts to rise.

2) If you are going to espalier it, follow the instructions in the Royal Horticultural Society's book: Pruning by Christopher Bricknell (references). Making your cuts in Springtime.

3) if it is a two-year old tree with branches, remove all branches below 18". Cut back the other branches to form a pyramid with the lowest branches being cut back to 12". Always make your cuts in Springtime.

Water well for the first two years. Keep area weed-free.

Once the tree has filled the space allotted for it, start Summer-Pruning using the Modified Lorette System (references).

How can I get an apple on my tree?

There are four stages to getting an apple: flower bud initiation, depositing of pollen on the stigma, pollen tube germination, and finally, fruit set.

Following are the optimum criteria for getting fruit on a fruit tree. Higher or lower temperatures, older or younger wood, more or less nutrients, less sunlight may produce a fruit, but that fruit is more likely to drop during the June drop or end up misshapen and/or small.

1. Flower bud initiation.

Before we can get any fruit, we must have flower buds. Apple and pear buds are 'mixed' buds when formed. They can become a flower bud or a leaf bud depending on how they are treated.

The flower buds which will open next April (2009) on apple trees were formed last May and early June (2008). Usually, apple flower bud initiation occurs during the six weeks after bloom time. The following are essential for flower bud initiation

a) adequate nutrients, especially nitrogen, boron, and zinc.
b) sunlight - flower bud initiation occurs only where there is lots of light; this is why dwarf trees are very good for flower bud initiation
c) the branches should have an angle of 45 to 60 degrees from the vertical. Very upright branches (e.g. water shoots) do not develop fruit buds.
d) don't allow too many apples to be set because the plant hormones in the seeds of the developing apples will inhibit flower bud initiation.
e) AND if you leave too many apples on the tree, the tree nutrients will go to the new apples and not to flower bud initiation
f) t
here must be plenty of two-year old wood on the tree every year.

Apple blossoms develop from mixed buds (buds which contain both leaves and flowers). The first blossom to develop and open is the King bloom (see drawing on left).

This blossom, if pollinated, will produce the biggest apple. There are usually 5-6 blossoms per cluster so if the weather is not good when the King bloom is out, there is a second and a third chance to get an apple from the secondary blossoms.

The temperature must be at least 14°C (57°F) for apple pollen to be viable and fertilize the ovule. Part of the pollen fertilizes the ovule and part of the pollen forms the flesh of the apple. Over time, this fertilized ovule will develop into a seed of the apple. The more ovules fertilized, the more seeds produced, the bigger and better the apple.

If pollination is poor and maybe only a few pollen grains arrive on the stigma, a fruitlet will be formed, but it will drop off. This is called 'June Drop'.

Only well-pollinated ovules will go on to produce an apple.

Artwork by Tish Davis, West Vancouver

 

2. Foreign pollen must be deposited on stigma

A few apple varieties are self-fertile and will produce some apples without another apple tree nearby. Most varieties need another apple variety that blooms at the same time planted nearby. Some apple varieties are triploids i.e. have sterile pollen. These triploids need two different apple varieties, that bloom at the same time, planted nearby OR (only) one crabapple that blooms at the same time. Even the self-fertile apple varieties will produce more fruit if there is another different variety nearby so cross-pollination occurs.

The Blue Orchard bees have fuzzy abdomens. When the bees are collecting pollen for their nests, they carry it on this fuzz and often accidentally leave some pollen on the stigma of each apple blossom they visit.

3. Germination of the pollen tube down the style.

If the temperature is above 14°C (57°F) and ideally 16-21°C(60-70°F).The pollen grows a long pollen tube which extends down the style to the ovule and fertilization occurs.

4. Fruit Set

In apples, double fertilization occurs - one part of the pollen fertilizes the egg and becomes the seed and the other part becomes the endosperm.

Crabapple trees are good pollenizers because they have lots of blossoms and the pollen has a high protein count. Some crabapples, e.g. John Downie, bloom over a very long period.

Following is a chart of the crabapple trees I have for sale in February 2010. Some are one-year whips and some are two-year old branched trees.

variety date flower bloom period frt size frt shape&colour ripens pers disease jelly tree shape r/s
Chestnut England 1921 red opening to white early 5 cm yellow? Aug no sl scab yes M26
Evereste France 1990? white mid 1.5 cm? red ? ? exc no arched branches, scab-immune Ant
John Downie England 1891 pink opening to white mid, long bloom 3 cm oval, orange Sept no good exc upright M9
Prof Sprenger Holland <1950 rose-pk to white, frag't mid, 12days 1 cm round, orange Sept-Oct no vg no upright, spreading Ant
Red Glow Canada? rosy bloom early-mid 2 cm purple-red,º Red Del Sept-Oct no yes upright, spreading Ant
Red Jewel USA 1972 white late, 13 days 1.2 cm cherry-red Sept-Oct yes sl scab no upright, pyramidal Ant
Snowdrift USA 1965 pink to white mid, 10 days .75 cm orange-red August-Sept yes sl scab no o/s in bloom, round to oval Ant

 



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