The pistachio, known commonly as Pistacia vera, originates from Central Asia and the Middle East. The plant is native to the desert and thrives in environments like the San Joaquin Valley of California that have long, hot summers and cool, dry winters.
Pistachio trees are deciduous with pinnately compound leaves. The flowers and fruits grow in large clusters. The internals of the nut are protected by a hard shell, which is in turn covered by a gold to red hull. Trees will reach a height of 20-30 feet at maturity, but can be pruned to control their height to a more manageable size.
Pistachios go through four stages in their annual cycle: dormancy in the winter, blooming in the spring, developing during the summer, and being ready for harvest in the fall. Trees produce fruit every year, but the amount varies from year to year, with fewer fruits produced in the second year after a large crop.
*/ There are two types of pistachio trees – male and female. The female tree can only set fruit if it is pollinated by a male tree. A single male tree can provide enough pollen for pollinating up to 11 female trees. Pistachio trees are mostly wind-pollinated, so they don’t need pollinators to produce fruit. Pistachios also have a chill requirement for flower development. They require at least 800 hours below 45°F.
How to Grow a Pistachio Tree
They are deciduous trees. Prior to planting your trees, you’ll need to dig a hole that’s twice as wide and just as deep as the root ball of your tree. If you’ve determined that your climate is right for pistachio tree growing and you have the space for two or more trees, you can get started by digging a hole that’s twice as wide and just as deep as the root ball of your tree.
Plant Pistachio Saplings
If you live in a climate that is good for growing citrus trees, you can buy young trees that are ready to plant at a local nursery or garden center.
To graft a new tree from an existing pistachio tree, the tree must be a minimum of 31 inches tall.
Growers are not always able to ship them to every state, but they can be found online. Many pet stores will sell you a male and female betta fish together.
Established plants are ideal because they’ve already been bearing fruit for years.
Plant from Seed
Some people prefer to buy pistachio seeds that are already germinated. If you decide to take this path, it is best to purchase from a nursery. You will need to plant multiple trees to ensure you have enough male and female trees, as you will not be able to tell the sex of the tree until it is time for it to bear fruit.
Remember that the germination process takes extra time.
You will need to plant your sapling or seeds when they are one year old. The best time to plant is between January and March. It’s relatively easy to do.
- Make sure the holes are as deep as the root ball and twice as wide.
- When you place the plant in the hole, it must be as vertical as possible.
- Use your fingers to lightly pull the roots off the ball and into the soil.
- Use all the soil from the container and mix in native soil.
- Water the soil as you put it back in the hole, which will prevent air pockets from occurring.
Remove any stones, weeds, or plants from the hole before filling it with soil to allow for growth.
You need a minimum of two trees to be successful with your orchard, but it is better to have several female trees for each male.
They need their space. Making sure there is enough space between them is important for their success. Space them a minimum of 12 feet apart.
Pistachio trees can grow up to 30 feet tall.
To ensure that male and female trees can pollinate each other, it is also important to space them properly. Too much spacing can prevent pollination from occurring. It is recommended that you plant your female trees within 50 feet of a male tree to ensure proper pollination.
How to Care for Pistachio Trees
To ensure the survival of a plant, you should water it regularly and give it enough sunlight. Once they are established, they require relatively little care.
Remember, they are dry-weather-loving trees. They are drought tolerant.
Because pistachio trees are native to areas with little rainfall, they do not need as much water as other species. water the tree once a week for the first two years with a deep soak. Pay attention to the soil moisture so you don’t encourage mold growth.
After the tree establishes, you may not need to water it as often. Instead of watering your lawn every day, it is better to water it deeply once a month.
You should water your plants so that the soil is moist up to four feet deep.
You can skip watering your garden altogether if your area has gotten a lot of rain in a given month. You can also stop watering your tree in the winter months when your tree is dormant.
Once the fruit sets, stop watering.
You should stop watering your tree in October to help it get ready for the colder months.
Pistachio trees thrive in areas that get a lot of sunlight. Pistachio trees need direct sunlight to grow well and to make the most of the hot, dry climate it prefers.
Pistachio trees are able to grow in almost any type of soil, though some types are better than others. For example, you should avoid wet and heavy soils.
Loamy soils that are light and sandy with a pH between 7.1 and 7.9 are ideal. Well-draining soil is a must.
Pistachio trees need to be fertilized with nitrogen, phosphorus, and potassium once each spring, starting in the second year. You can add 10-10-10 NPK fertilizer.
You may want to test the soil before taking any action. A soil test is helpful in determining which nutrients it is lacking and how to adjust fertilizer accordingly. Nut trees require nitrogen to thrive.
The male pistachio tree produces pollen, which is then dispersed by the wind and eventually reaches the female tree. The pollen fertilizes the ovules in the female tree, which then go on to become the pistachio nuts. Pistachio harvests are healthier in areas that experience gusty winds.
While more intense storms can interfere with pollination, it usually occurs from early to mid-April.
Pistachios need to be pruned for optimal growth and production. Pruning should be done in winter when the tree is dormant and dead or dying branches should be removed. In addition to removing branches that are touching the ground, also cut any branches that are crossing over each other.
Otherwise, prune when branches are six feet long.
Try to prune only where strictly necessary. If you cut off too many branches, it can damage the tree’s ability to produce nuts. Remember that it is important to prune when the plant is dormant, but it is also okay to do some light pruning during the summer.
Budding is a technique used to optimize pollination. Grafting involves taking parts from two or more plants and joining them so that they appear to be growing as one plant.
Many professional growers find it beneficial to combine different rootstocks and scions. The bottom part of the plant that creates roots is called the rootstock. The top part of the tree, which determines the fruit characteristics, is the scion’s responsibility.
Pioneer Gold 1 and UCB-1 are popular rootstocks, and they may help prevent diseases like verticillium wilt.
Harvesting and Storing
Harvesting pistachios is very easy and rewarding.
Pistachios are ready to harvest when the hull turns red and the hull splits, exposing the shell. To harvest pistachios, lay a tarp below the tree and shake the branches until the nuts fall.
Pistachios shouldn’t be allowed to land on the ground since they split before being harvested, as this increases the risk of contamination. Remove the hulls immediately after harvest. If you don’t remove the hulls, the shells will get stained and there might be mold growth. It also slows the drying process.
Pistachios need to be dried and stored in an airtight container to keep them fresh. Pistachios can be dried by placing them in the sun for 3-4 days or by placing them in the oven at a temperature of 140-160°F for 10-14 hours.
Pistachios stored at room temperature will remain fresh for several months. To store eggs for up to a year, keep them in the freezer with or without the shell.
Growing pistachios is usually problem-free. If you run into any issues, here are some possible solutions.
Weather conditions are the primary reason for reduced or no crop yield. If it’s warm during the dormancy period, the tree won’t produce flowers. In order for trees to thrive, they need a minimum of 800 hours of exposure to temperatures that are below 45 degrees Fahrenheit. If the tree doesn’t get enough chill hours, then it won’t flower as well. Temperatures that are too high during the dormant season can cause flowers to fall off.
Low pollination rates can lead to reduced fruit production. Pistachios are largely wind-pollinated. The location where the plant is placed should be considered to ensure that it will be properly pollinated. Do not place male trees near a wind barrier or downwind from female trees.
Navel orangeworm adults are moths with gray wings and black markings. Moths lay eggs inside split shells. The larvae of the pistachio twig girdler are reddish-orange or cream-colored and feed on the pistachio nut. This pest can be managed using cultural methods. Old nuts from the previous year should be removed to prevent or reduce overwintering pest insects. If you harvest the nuts immediately after the hulls have split, the pests will not have a chance to lay eggs in them. You can use Bt to control pests if you need a chemical spray.
Oblique-banded leafroller is another moth pest of pistachios. Adult moths are brown with darker brown zigzag bands on their wings. The larvae feed on leaves and flowering branches. The damage to the leaves will be very evident; they will appear to be rolled or tied up. The larvae can be found inside the rolled leaves. Larvae are yellowish-green with dark heads. Bt is very effective in controlling pests. Spraying once a week may be necessary until the problem is solved.
In Victoria, it is often seen on grapefruit, mandarins and lemons. A small reddish mite that is often seen on grapefruit, mandarins and lemons during the summer months in Victoria. Mites feed on the stems and nuts of clusters, causing them to shrivel. Clusters that are damaged are more likely to stay on the tree instead of falling during winter. This provides a shelter for the navel orangeworm and fungal pathogens. If the citrus flat mite needs to be treated, you can use sulfur sprays.
You can find soft scales on the twigs and branches of trees. There are several species of soft scale insects that come in a variety of colors, from yellow to brown to black. Damage does not come directly from the scale. Scales excrete a large amount of honeydew, which leads to the growth of sooty mold. The leaves are covered in sooty mold, which prevents them from being able to photosynthesize. This leads to the leaves falling off the plant. Scales are usually controlled by natural predators and parasites. If treatment is necessary, dormant oil sprays are effective.
Mealybugs and soft scales both excrete large amounts of honeydew, which leads to the development of sooty mold. Mealybugs typically reside in the shoots and fruit clusters. Mealybugs are white or gray with a white waxy coating. Nymphs that emerge in June are typically the most mobile stage. If natural predators are unable to keep populations under control, a chemical called pyrethrin can be used for control. Pesticides are most effective when applied during the crawler stage.
The two most common foliar diseases in pistachio trees are botrytis and alternaria. Both of these diseases cause the leaves and shoots to die back. Diseases that occur in damp conditions are caused by either constant rain or high humidity. The best way to stop them is by keeping leaves and branches dry, and by pruning trees so there is good air circulation between branches and leaves.
The most common root diseases in pistachio trees are Phytophthora and Verticillium.
Verticillium starts in the roots, and if the infection isn’t caught early, it will spread to the xylem. The infection will prevent the plant from taking up water and nutrients, causing it to wilt and die. There is no way to cure Verticillium once a plant has it, so it is important to take steps to prevent the disease in the first place. If Verticillium is present in the soil, a rootstock that is resistant to Verticillium must be used to avoid infection.
Phytophthora is a common issue that causes root rot. This fungal issue can be prevented by watering properly and having good drainage. The symptoms of Phytophthora above ground include reduced vigor and yellow leaves.
Pistachio nut trees are low-maintenance, but there are some tips you should keep in mind to help them grow.
Weeding around the trees is important. If there are weeds around the trunk of a tree, they can hold moisture there and cause the tree to get a fungal disease.
Pests are attracted to fallen fruit and leaves, so removing them will help keep pests away from the area around the tree.
Overhead irrigation systems are not ideal for pistachio trees. Damp leaves and bark make it more likely for plants to get sick.
Others choose to plant them directly in their final location Some growers prefer to plant seedlings in containers at the start of the tree’s life, where they can stay for 3 – 5 years. Others choose to plant them directly in their final location. Although the plant has a long taproot, it cannot be grown in a container for a long period of time. Once this period has elapsed, it is crucial to transfer them to the garden so they can complete their journey to maturity.
Start small. You don’t need a lot of space to grow pistachios. A pistachio tree that has reached full maturity can produce up to 50 pounds of nuts. Start with at least two trees. If you have the budget and enough space, you should plant more.