I recently was reading about pear trees and found they often get brown leaves. I wanted to find out more, but I couldn’t find much helpful information out there. So, I dug in a little deeper. Here’s what I found.
Pear trees get brown leaves most often from a lack of water. However, other stressors such as extreme weather, pests, and diseases can also cause it. Typically, if the leaves look dried, it’s likely a lack of water. If the leaves look burned, it’s likely fire blight. Proper prevention is the best way to avoid disease.
So, while pear trees get brown leaves from several causes, how can we tell which issue is causing it, and how can we fix it?
When pear trees are under-watered their leaves typically start to curl and yellow before turning brown and falling off. The browning usually starts at the tip of the leaves before moving down the rest of the leaf.
If not watered sufficiently for an extended period, the pear tree’s leaves will continue browning and dropping, before getting to a point where it can’t photosynthesis. While the tree can still grow new leaves from stored energy, it will soon run out, at which point the tree begins to die. During this process, the tree also becomes more vulnerable to pests and disease.
So, what’s the optimal way to water pear trees?
The best way to water pear trees is by only watering when the top 2-4 inches of soil is dry. You can use a finger to test the soil’s moisture. This prevents both under and over-watering. When watering, make sure the ground gets soaked to about 2 feet down (the depth of the majority of the roots).
If your pear tree’s soil has good drainage, providing compost and mulch are two practices that are a must-have.
Compost is great at not only providing sufficient nutrients (more on this later) but increasing the soil’s richness—every 1% increase in the soil’s richness holds an additional 20,000 gallons of water per acre (source).
Mulch brings benefits such as regulation of soil (and root) temperature, reduced evaporation, and added nutrients once the mulch breaks down.
Remember to keep the compost and mulch at least 3 inches from the tree’s trunk to prevent moisture build-up (which can lead to mold on the trunk).
If you haven’t yet planted your pear tree in the ground, and your soil has poor drainage, it’s usually best to plant them in a mound of soil. For more information about planting in mounds (and why this is best in clay soils), check out my post: Can Fruit Trees Grow in Clay Soil (& How To Plant Them)?.
For potted pear trees with poor drainage, it’s usually best to repot them with fresh potting soil. Due to being confined to a pot, they typically experience much less transplant shock.
So, if your pear tree’s leaves are curling, drying, and browning, under-watering is the more likely issue.
Although stress from over-watering can induce brown leaves at times, its symptoms typically include dropping green leaves. Either way, checking the soil’s moisture before watering is the best way to prevent both under and over-watering.
Generally, pear trees can handle temperatures between -30ºF and 90ºF but get stressed when there’s an early frost, extreme heat, or a swing in weather. This stress causes the tree’s leaves, blossoms, and fruit to brown and drop. To prevent this, monitor swings in weather and shelter the tree if possible.
For best results, keep your pear trees between 45ºF and 80ºF during the spring and summer.
When pear trees get too hot, their leaves start to burn and the soil will likely dry. Dry soil makes the issue even worse as the tree’s roots can’t send moisture to its leaves and help cool them.
On the other hand, pear trees can tolerate cold temperatures fairly well due to them being deciduous trees. As deciduous trees, they shed their leaves in the fall and enter dormancy to survive through the cold winters (much like how bears hibernate).
Because of this, pear trees do best in USDA hardiness zones 4-8, but most varieties can survive in zones 3. Also, like other deciduous trees, pear trees require a certain amount of chill hours per year to grow and fruit properly—about 200-800 hours.
However, too much cold will kill pear trees. Typically, pear trees will be dormant for the winter and have a good chance of surviving it, but an unexpected frost outside of dormancy can damage the tree.
For example, pear trees that are woken from dormancy mid-winter will start growing again, only to suffer from a later frost. This can stunt the tree for a season or kill it if severe enough. Pear trees will have their dormancy broken if temperatures reach 45ºF or higher.
If your climate gets too hot or cold for your variety of pear trees (typically outside of -30ºF to 90ºF), there are some steps you can use to help protect your tree.
Hot Weather Tips
- Provide 2 inches of compost and 4 inches of mulch. Compost provides valuable nutrients and increases the water retention of the soil (source), while mulch regulates soil temperature and reduces evaporation. Reapply compost every 1-2 months and mulch every 3-6 months.
- Shade pear trees from the afternoon sun. Since the western, afternoon sun is much hotter than the eastern, morning sun, shade the tree for a least a few hours from its west side. Some ideas to shade are large umbrellas, shade sails, or other trees.
- Move potted pear trees indoors during heat waves. Try to move them gradually over two weeks as to not stress them out from the swing in temperature. If you can move them to a patio with shade, that’s even better.
Generally, while hot weather more commonly leads to brown leaves, extremely cold weather can also cause it.
Cold Weather Tips
- Insulate the tree’s canopy with bedsheets or the trunk with cardboard during times of frost. Plastic tarps also work well, especially at preventing ice build up.
- Bury the pot or provide a mound for planted trees. Potted pear trees can be buried outside in the ground for more insulation. You can also place the pot in a box and pack in the remaining space with mulch. Planted pear trees can benefit from a 1-2 foot high mound of mulch such as leaves during the winter.
- Place pear trees along a southern-facing wall for maximum sunlight and warmth. Generally, facing south allows for the most sunlight (as it receives both the sunrise and sunset). Also, as night falls, some warmth will continue radiating from the wall onto the tree.
- Avoid bringing potted pear trees indoors during the winter as they require chill hours. Indoor temperatures, including basements, rarely fall and stay below 45ºF necessary for chilling.
Pests and Diseases
Pests and diseases such as aphids, mites, rust, and fire blight cause pear trees to get brown leaves. Most pests can be repelled with water, oils, or sprays, while diseases can be treated with organic sprays or fungicides. Some pests and diseases such as aphids can be deterred with companion plants like garlic.
Generally, you can tell if your pear tree has a disease by inspecting the leaves for any yellow or brown spots as well as deformities.
You can also typically tell if pests are infecting the tree if you see them gathering on the underside of the leaves (like aphids) or holes in the tree (like borers).
On the other hand, if you notice your pear tree getting dark green, brown, or black spots, it could be caused by other diseases such as pear scab, sooty blotch, and fire blight.
While our first instinct is often to panic and prune the pear tree of all signs of disease, it’s not the only way.
Mark Shepard, on his 100+ acre farm, uses a method called STUN (sheer total utter neglect) and it works wonders for him. He uses no chemical fertilizers, sprays, or any other dependencies. Through the struggle, his fruit trees become stronger and his job gets easier.
Check out the below video for more about Mark Shepard.
Also, if you’d like more information about pear tree pests, check out this resource by the University of Maryland Cooperative Extension. For pear tree diseases, try this resource by The Connecticut Agriculture Experiment Station.
Again, you can also reach out to your local cooperative extension for more details about the specific issues pear trees get in your area.
A Note on Pesticides, Herbicides, and Fungicides
My parents recently had an issue with caterpillars eating their basil plants in Ventura, CA, and they were about FED UP. Every time they’d plant basil, the caterpillars ate it. Fortunately, instead of giving into chemical sprays, they found an organic spray at their local nursery that’s made from fermented rum. The day after spraying, they’d find dead caterpillars on the soil.
If you’d like to find out more about this organic spray, you can find it here on Amazon.
So, what’s my point here?
Even though chemical sprays and fertilizers are an easy way out, like all easy and convenient things, there are usually long-term costs. Namely to the plants, soil, and surrounding beneficial life. Before using conventional sprays, weigh the pros and cons and consider using organic or permaculture-based treatments first.
To give you a head start, Stefan Sobkowiak – The Permaculture Orchard has a great video on a safe, homemade, and most importantly—effective fungicide (hint: the secret ingredient is whey).