The Practical Gardener

Jan 30, 2016

It's the time of year to finish all the tree chores you've been putting off.
Credit David Lofink / Creative Commons

It's hard to believe, but the calendar says there are less than 50 days until spring. If you're at all like me, with all the welcomed winter rain, you haven’t spent too much time working in the garden — so now we're getting down to crunch time to get those winter orchard chores done.

What are the things do you need to be doing? The first thing: if you haven’t pruned your fruit trees yet, get that done. You have until about the middle of February to take advantage of the beneficial effects of winter pruning:

  • It helps trees become structurally sound with strong limbs to carry fruit load.
  • It helps to control size for easier care in maintaining and picking fruit.
  • It helps to distribute sunlight evenly throughout tree.
  • Pruning regulates fruit bearing by removing excess fruitwood.
  • It also helps to renew and replace old fruitwood.
  • And lastly pruning removes undesirable wood — dead, broken, and crossing branches.

But if pruning seems a little daunting, just remember, there are only two types of pruning cuts: thinning and heading.

  • Thinning cuts are used to remove lateral branches at their origin or to shorten branch length by cutting back to another lateral that is a minimum of 1/3 the width of the branch section being removed. Usually thinning cuts are used to take out larger branches.
  • Heading cuts are when a plant is cut back to a stub, lateral bud or small lateral branch. Heading cuts may result in a flush of vigorous, upright growth. Heading cuts are most often used in fruit trees to top them and keep the trees short.

The next major thing that should be done, especially because of all the wet days this winter, is a dormant spray. There are two goals with dormant season sprays. The first is to control overwintering insects like San Jose scale, peach twig borers, and aphid and mite eggs. 

The second goal is to control early season diseases such as peach leaf curl and brown rot and perhaps reduce the incidence of bacterial canker. 

To control overwintering insects the ideal spray is just a Supreme Dormant Oil spray. If scale populations have been significant, you should tank-mix in spinosad with your dormant oil spray (spinosad is a natural substance made by a soil bacterium that can be toxic to insects).

To control the problem diseases, spray with fixed copper or tank-mix fixed copper with your oil spray.  These sprays should be on at bud swell, but before the buds show any color. You're on a quick timeline here to get these important tasks done before your fruit trees are in full bloom. 

You may need to treat more aggressively at and during bloom if it is a very wet spring.  There are fungicides on the market that can help with things like powdery mildew, pear scab, shot hole fungus and so on.  Please read the label fully for details in timing and application.

For a more detailed Calendar of Backyard Orchard Operations, go to homeorchard.ucdavis.edu