We are fortunate to be able to grow many different types of plants here in Tucson. We have a nearly tropical climate, but we do get some freezes in the winter. This allows us to grow a wide range of fruit, including deciduous fruit trees.
March is the perfect month to plant deciduous fruit trees, especially bare root ones that are now available in nurseries. Bare root trees are usually cheaper, and there may be more varieties available for sale.
Our climate and environment does have some quirks, however, which make it a bit difficult to grow certain fruits. For one thing, our soil is more alkaline than most deciduous fruit trees like. We also have a lot more sun than climates further north. And, obviously, there’s less natural precipitation, meaning that fruit trees need supplemental water to grow here.
Perhaps the most important limitation we have is the number of chill hours, which are defined as the minimum period of cold weather (usually below 45 F) that a deciduous fruit tree requires to develop flower buds in the spring. If the chill hour requirement for a particular tree isn’t met, the tree will develop few, if any flowers, and thus very little (or no) fruit.
Thus, growing deciduous fruit trees in Tucson isn’t exactly plug-and-play. I spoke with Pima County Master Gardener Deb North to get some tips on selecting, planting, growing and harvesting deciduous fruits. Here are some tips she shared with me to help you grow the best deciduous fruit trees.
What trees should I select for my yard?
“Buy a fruit you like,” says North. It may seem obvious, but given our limited water, you don’t want to spend all your cash watering a tree whose fruit you don’t particularly like. In addition, North recommends thinking carefully about the mature size of the tree. You will have options like full size trees, or dwarf and semi-dwarf varieties. “You need to figure out how much fruit you want,” says North, and you also need to consider how you will harvest that fruit. “If you’re going to get a full standard (size), that says you’re going to be up on a ladder, either pruning or harvesting.” Full size trees can also get tall and broad, so you may not have room for them in your yard. They will require more water. And don’t forget about the leaves, which will drop every fall.
But the most critical aspect of your chosen tree will be its aforementioned chill hour requirements. “If you purchase something that has like a 500 chill hour, 600 chill hour (requirement) you’re not going to get fruit here,” says North. “A safe bet is 300 (chill hours) or fewer; figs typically only need 100 to 150.” She also recommends checking the rootstock on the tree you’re buying to make sure it can tolerate our dry conditions.
Bare root trees are usually available in the late winter and early spring in Tucson. These are cheaper, North says, but make sure you do your due diligence and purchase varieties that will do well in our climate. You can check out a list of these varieties, along with their chill hours, in the Pima County Extension’s handout, “Deciduous Fruit & Nuts for the Low Desert.” The handout also tells you whether the trees are self-fruitful (most are) or whether they require another tree to be pollinated.
How and when should I plant my fruit tree?
If you’ve purchased a bare root tree, North says it’s critical to keep the roots wet until you plant it. “Once you clean off all the debris that comes in the bag, you soak them in water overnight and then you have your planting hole ready and dug, with a cone in the middle,” says North. The cone is an area of earth raised up a little from the surrounding hole. You should plant your tree where it will get about six hours of sunlight, preferably in the morning.
North also recommends trimming a bit off the main roots with very sharp bypass pruners before placing the tree in the soil. “You want to get rid of any roots that are broken, damaged, look dead, or if anything smells bad,” she says.
Make sure your tree’s bark isn’t buried under the soil. North recommends having someone help you, so that person can keep the tree straight as you’re filling the native soil in around the roots. The Pima County Extension no longer recommends adding any amendments to the soil when planting any tree. Instead, North says, put compost and mulch on top after you’ve planted. This will get worked into the soil by tiny soil dwellers and will enrich the soil around your tree.
“I like to put down compost on top of the soil, then the watering system, and then mulch on top of that,” North says. Keep the compost and mulch about 2 inches away from the tree trunk to avoid any bark damage. The watering should be placed around the drip line of the tree’s canopy, and should be adjustable, so you can move it outward as the tree grows.
Bare root trees need to be planted as soon as possible after getting them home. North says you can plant container trees almost any time of year, but she advises against planting in the late spring during our hottest weather. Fall and early spring are the best times to plant non-native trees. For more tips on tree planting, take a look at my article “The best way to plant a tree in Tucson.”
How do I fertilize my fruit tree?
Don’t fertilize the tree at all in its first year, to give the roots time to develop and the tree time to get established. You can still add compost of any kind, though. North says you probably shouldn’t expect any outward growth until the tree’s third year. She fertilizes her fruit trees four times a year, starting on Valentine’s Day, and continuing every two weeks. “I do February 14, the 28th, the 15th of March, and the 30th of March,” North says.
She uses organic fertilizer, usually in the form of some type of manure. She recommends fertilizer with equal amounts of N-P-K—that is, nitrogen, phosphorus and potassium. “Deciduous fruit trees, they flower and they fruit, which means they need all three numbers on the front of the (fertilizer) bag.” An all-purpose, balanced fertilizer should do. She also composts around the tree as needed, and periodically adds worm castings as well as kelp meal to increase the organic matter in the soil.
How do I prune my fruit tree?
Shaping a fruit tree with pruning is a little more complicated than this article can get into. North gives lectures on fruit tree care and pruning for the community, so you can sign up for one of those or contact the Pima County Cooperative Extension for more information. The extension also has a thorough and helpful handout “Training and Pruning Newly Planted Deciduous Fruit Trees.”
There are some basics that everyone should know. While it’s best to prune deciduous fruit trees when they’re dormant, you can do a bit at other times of the year if you need to, says North. She also recommends that gardeners learn what type of wood the fruits grow on, as this varies with different species. “Peaches typically grow fruit on year-old wood,” she says, while pomegranate fruits on new wood. With figs, “you get two crops: The first is on year-old wood and that occurs earlier in the summer. And then if you’re really lucky, you get a second crop but it grows on the newer wood.” Needless to say, you need to keep this in mind when pruning, so you don’t cut off all of your fruit-bearing wood.
When do I pick the fruit?
This will depend on the type and variety of fruit you’re growing. For example, apples can ripen anywhere from spring to late summer or early fall. Different fruits will also look different when they’re ripe, so read up on your variety. “You need to understand the color of your fruit when it’s ripe,” says North. She has a secret weapon for her fruit harvest, though. “I have a dog that’s very helpful in figuring out when things are ripe.”
What can I do about birds eating my fruit?
The Master Gardeners do not recommend netting because it kills birds and small animals, which get snared in the netting and die of exhaustion and exposure. Instead, North mentions a number of different options.
North uses inexpensive Mylar tape on spools, which she cuts into strips and ties onto her tree branches. You can also use holographic tape or bird-scare tape, which are essentially the same idea. She says that vine growers in California use this method, and it seems to be effective. “I have experimented where I’ve done half of my tree with the tape and half without, and I can tell you there’s a difference.”
You can also protect the fruit once it starts developing. Gardeners can purchase small mesh fruit bags which they then put onto the fruit before it ripens. “The other thing people do is they save the clamshells [when] they purchase other fruit,” North says. These clear plastic containers can snap into place around your fruit, letting light and moisture in but keeping birds out.
She also recommends that gardeners share some of their crop with birds. If your tree is producing lots of fruit, chances are you can let the birds have some.
Do I need to worry about frost?
Not in Tucson. These trees come from climates much colder than ours and can take the little bit of cold that our early spring can throw at them. Even if your tree buds out just before a frost, North says you shouldn’t worry. “Our freezes are so minimal…you don’t have to get out there and cover them and risk losing those flowers.”
Dried fruits come in many varieties. Here are three dried fruits with amazing health benefits.
