One of the garden components that grows best in the bay area versus other parts of the world are fruit trees. We have the coveted climate to grow most types of fruit trees and we find them in most of the bay area gardens. In our experience, the proper care of them is often misunderstood. In this month’s newsletter, we are going to provide some important details that maximize the health and longevity of your fruit trees and hopefully make the care of them easy and clear moving forward.
Here, we’ve compiled responses to some of the frequently asked questions we encounter while supporting our clients in the care and management of their fruit trees.
5 Most Common Questions We Get Asked
When To Prune?
Pruning is an important component of fruit tree management. If you begin pruning it at a young age, you can train it to be the size that’s easiest to pick from and develop a structure that maximizes space for fruit production. Pruning is important during all ages and stages of the tree’s life.
- Winter is generally the optimal period for pruning most fruit trees—specifically, during the interval when the leaves start to drop and before the buds develop into blossoms or new leaves. This typically occurs between November and February.
- The exception is for Apricot Trees. It’s best to prune these in the summer after fruiting. This helps prevent them from acquiring fungal pathogens during the fall seasons when fungus is active and there are open pruning wounds.
- Citrus trees are also hard to time. They always seem to have fruit and do not go dormant. Its best to prune in the winter right after the fruit ripens so it can all be picked and then pruned.
- Light pruning can occur all throughout the year on all these trees, but a major prune is best done in winter.
How To Water Fruit Trees?
This is another area that is often misunderstood but can have immense impacts on the tree’s health. These recommendations will be directed at mature fruit trees.
- Watering should begin in the spring when the rains stop and end in the fall when the rains begin.
- During that time frame its best to water no more than once a week.
- Watering should be focused on deep penetration that percolates to the lower 12” of soil. This might require 10-20 gallons of water per session depending on the size of the tree. Avoid watering shallow and frequently. This type of watering does not supply the tree with nearly enough water and forces the roots to come to the surface rather than growing deep.
- Water the tree from the outer branches to the inward trunk. We call this the drip line. The roots are often well beyond the canopy so watering a larger area is important to reach the majority of roots. To prevent the risk of root rot and ensure adequate hydration for the entire root system, refrain from exclusively watering around the trunk. This practice, if repeated multiple times a week, only reaches a portion of the roots.
- Adding mulch to the area under the tree canopy and aerating the soil can also help improve the water’s penetration into the soil and roots. Aerating the soil involves loosening the soil to a depth of 2-4”. A natural mulch can be applied under the canopy to a depth of 3-4”. This will help retain moisture during the summer months, avoid soil compaction, and add beneficial nutrients to the soil.
When To Treat For Insects And Pests?
The best time to treat trees for insects and pests is before they are present. In the bay area we are prone to acquiring all types of pests and diseases. If trees are cared for properly and treated at the right times they can be prevented or managed if already present.
Here are some of the best times for treatment:
- When treating for fungus its best to treat before the leaves emerge. Begin treatments after pruning in the fall and continue until the buds break and leaves emerge. Depending on the fungus being treated, it may require multiple applications in the fall. Treatment after the leaves emerge is also helpful with a persistent fungus such as leaf curl or mildew. We always use organic products on fruit trees as well as Copper fungicide or neem oil which tend to be the best options.
- When treating for insects, it is also best to begin in the fall seasons. We are usually treating for aphids, scales, or mites. Using horticultural oils in the fall and neem oils in the spring and summer have great effects. Treating for these proactively will help prevent them and if your tree already has them, treatment should eradicate if applied at the correct times.
When To Fertilize?
- Fertilization is important to ensure the soil has sufficient nutrients to supply the tree with the fuel for growth. Fertilization can be applied using organic products such as manure or compost, or a combination of organic and inorganic with granular fertilizer.
- Applying organic products can be performed at almost anytime of the year because they are slow release and it can rarely be over applied. Amending these products into the existing soil is the best way to apply.
- Applying granular fertilizer is best applied in the early spring and then again in the late summer. Depending on the product used it should provide details on the quantity to apply. It’s always important to water the tree heavily after fertilizing to ensure the product is immersed into the soil. These products can usually be picked up from a local nursery or hardware store.
- Applying them beginning at the drip line and then up to 18” from the trunk is the best area to treat. It’s similar to the area to water. The goal is to reach the majority of the roots and not allocate into a small portion of the area.