Typically thought of as nuts and used as such in recipes, almonds are really stone fruits with an edible kernel encased inside the hard pit. When compared to others in the stone fruit family, such as plums and peaches, almond trees are the earliest to bloom and make attractive and fragrant landscape additions.
What the Trees Look Like
Almonds (Prunus dulcis) are native to the Mediterranean climate areas of the Middle East and Western Asia, forming into small deciduous trees. Common names for the tree and fruit include almond and sweet almond.
Foliage and Form
Almond trees are fast-growing and average 15 feet tall and wide at maturity, making it suitable for smaller landscapes. Trees can have single or multiple trunks giving way to an open and often spreading canopy. Serrated foliage is lance-shaped, growing up to 5 inches long and changes to a yellowish color in fall before it drops in winter.
Before the tree fills out with foliage in early spring, white to pinkish fragrant flowers form along the shorter lateral branches. Each flower has at least five petals.
Despite the flowers being monoecious, which means each one has male and female parts, two different types of almond trees are necessary for proper pollination and the production of fruit.
It begins producing fruit around three years of age and can continue producing fruit for 50 years. Each pollinated flower turns into a drupe which contains the entire fruit, held close to the branch. It takes each drupe about eight months to mature and be ready for harvesting.
Once the drupe ripens, the outside hull splits open, revealing the nut inside. Cracking the nut reveals the edible kernel inside, commonly called an almond.
Common Types for Cross-Pollination
Since these trees require a different type for proper pollination and fruit-production, grow two different types in close proximity of each other. If your neighbor has a different type, you can probably get away with having just one tree in your landscape, as their tree will assist in the pollination and helped by local pollinators like bees. Some common types of almonds suitable for cross-pollination include, Alrich, Wood Colony, and Fritz for Nonpareil types, among others.
Purchasing an Almond Tree
When shopping for the plant at your local plant nursery, look for healthy trees that don't show signs of pests or diseases on their foliage. The foliage should be green and healthy looking without signs of leaf spots or curling. Make sure the root system hasn't outgrown the container which generally shows by roots growing out of the bottom drain holes. You are most likely to find 1-year-old to almost 3-year-old trees for sale at local nurseries.
If you can't locate the tree at your local nursery, you can purchase one through an online plant dealer. Online almond trees are generally around 1-year-old and shipped while in the deciduous state. Plant sellers include Willis Orchard Co. and Stark Bro's, which carries several cultivars.
Basic Growing and Planting Requirements
Almond trees are hardy in USDA zones 7 through 9 and grow best in locations within these zones experiencing a long growing season. Areas where frosts in early autumn and late springtime are common are not suitable as the tree will not produce a crop of almonds due to the cold weather.
Selecting a Location
Consider the almond's mature size and width when selecting its permanent location in the landscape. Allow enough space around the tree for proper air circulation because this can help avoid problems with diseases and pests. Do not plant the tree where it will interfere with utility lines or structures. Though classified as small to medium-sized trees, you want to plant the almond in a location where it has enough room to develop its mature shape and size without interference.
Sun and Soil
Plant the tree in a location receiving full sun throughout the vast majority of the day. Almonds won't grow or bloom well in locations situated in shade. Generally, six to eight hours of sun each day is sufficient for proper growth and production of fruits.
These trees grow well in soils that have some fertility and drain well. The tree will not grow well in soils that retain too much water, or are constantly waterlogged. It will develop rot and eventually die.
For the best growth, almond trees require regular applications of water throughout the growing season. Water the freshly planted tree one or two times a week until the root system establishes itself in approximately two to three months. Thereafter, water the tree weekly.
Though you can plant the tree throughout the year, planting during the months of January and February are best. This gives the tree's root system time to begin establishing itself into the planting site before the foliage begins its growth.
Once you've selected the appropriate location, remove any grass or weeds from an area large enough that lawn equipment won't damage the trunk. Unwanted growth robs the tree of necessary nutrients and can harbor diseases and pests. Keep the area vegetation-free through regular weeding.
Handling the Roots
Check the almond's root system before planting and trim off any that are broken. Trimming down the root system's size before planting is not necessary and this procedure can delay the tree's establishment and harm its rate of growth. Always use sanitized pruning tools so you don't transfer disease to the tree.
They are susceptible to crown gall and disinfecting the entire root system with the product Galltrol helps in preventing the disease. Before planting, saturate the entire root system with the product. You can apply by spraying it on the roots or creating a bath for dipping the entire root system.
Planting in the Hole
Dig a hole that is wide and deep enough to house the entire root system without any bending. Since the root system is sensitive and you don't want to damage it by forcing it into a hole too small, it's better to dig a hole a bit bigger than have one too small.
Place the root ball into the hole and gently spread the roots. Plant the tree at the same depth it was growing in its original purchased container and not any deeper or you place undue stress upon the tree. Fill the hole halfway with soil and firm it up around the roots using your hands. Water the hole to settle the soil around the roots and release and air pockets and then fill the remainder of the hole with soil. Once planted, thoroughly saturate the planting site with water.
If you decide to mulch around the tree, make sure to keep it approximately 6 inches from the trunk. Butting mulch against the trunk can cause rot problems. Mulch serves to retain moisture in the soil and helps keep undesirable vegetation growth at bay. Apply approximately a 3-inch layer over the planting site.
Other than controlling diseases and pests, the main continued care is pruning and applications of fertilizer.
Most of the pruning takes place in at the end of winter or the beginning of spring before buds break. It is important to do major pruning while the tree is still in its dormant stage. Trim off any crossing branches and thin branches inside the canopy to open it up for better circulation of air and light. Trim the branches back to a main branch. This is also a good time to remove any diseased, damage or dead branches.
However, prune off any dead, damaged or diseased branches year-round and as they appear. To keep from transferring diseases to the tree, always use sterilized pruning tools to make your cuts.
The trees require three applications of fertilizer throughout the growing season spaced about three months apart. Wait to fertilize newly planted trees until the tree produces several inches of new growth. Use an all-purpose nitrogen fertilizer and spread 4-ounces evenly under the canopy, avoiding applying the product close to the trunk. Apply the first application in the first part spring and end with the last one in late summer. Always water the fertilizer into the soil after applying.
Harvesting the Nuts
Once the tree's drupes begin splitting open, you can begin harvesting the bounty. Lay a tarp or sheet under the tree to catch the fallen nuts. Shaking the tree or branches will release the ripe fruit from the branches and they will fall onto the cover on the ground.
Dry the harvested almonds by spreading them out on a sheet in a protected location where wildlife can't get to them and allow the almonds to air dry for a few weeks. Once dried, you can store the almonds in their shells or shelled for several months in an airtight container. You can also freeze the almonds and they will remain fresh for several years. Freezing the almonds for several weeks also kills any worms that might have taken up residence inside the shell.
Pest and Disease Problems
A variety of pests and disease problems can affect almond trees. As with many problems, proper care of the tree such as water and fertilizer keeps the tree healthy and can prevent some problems from occurring. Keeping the area under the tree free of fallen nuts and leaves also helps in keeping the tree pest- and disease-free.
Common diseases affecting the trees include:
- Crown gall: The crown gall bacteria enters the tree through a wound. The problem is most serious for young trees. However, older trees can be affected and the galls lead to decay, which then leads to stunted growth and rot. Galls form on the trunk with branches becoming soft and eventually rotting. Once the galls form, gardeners should treat the infected areas with Gallex. Prevent the problem by not wounding areas of the tree by lawn equipment bumping into the trunk.
- Shothole fungus and leaf spot: Shothole and leaf spot fungi can overwinter on plants causing lesions and purplish or dark spots to form on foliage and fruits. The spots eventually give way to a hole. If left untreated, the fungus affects fruit production and can cause leaf drop. Control the problem by spraying the entire tree in winter and before bud break with a copper fungicide.
- Blossom blight fungus: Blossom blight fungus affects the flowers, nuts and can affect the production of each. Both the flowers and nuts affected with the fungus show symptoms by having small brown spots that eventually take over the entire flower or nut. The fungus overwinters in the soil and proper cleanup of fallen fruit and leaves helps in prevention. Spraying the tree in early spring before bud break with a copper fungicide helps in preventing an outbreak.
- Powdery mildew fungus: Powdery mildew is most prevalent when conditions are warm and humid. The fungus is transported through the air and lives in the fallen debris under the almond tree. It is easily recognizable because it looks like flour covers the foliage and can cause stunted growth, distortion of the leaves and flower buds. Prevent the problem by cleaning up fallen debris under the tree and not watering the tree's foliage. Treat the problem by spraying the entire tree with a neem oil fungicide.
Common Pest Problems
Various insects infect almond trees, including sap-suckers, borers, and caterpillars. As with any pest problem, early detection and treatment is the best course of action in getting rid of the problem.
- Aphids and spider mites: These pests suck sap from the tree's foliage and stems and cause discoloration in the foliage, leaf curl, and distortion and stunted growth. Aphids and spider mites congregate on the undersides of newly developed leaves and tender shoots, sucking the plant's juices. Spider mites leave a fine white webbing. Pear-shaped aphids come in a variety of colors including green, black and yellow. Try to blast them from the tree by using a strong blast of water. In the event of a severe infestation, spraying the plant with insecticidal soap and treating every week should control the pest problem.
- Scale: Like aphids and spider mites, this pest sucks sap and creates the same issues. Scales are circular with an armor-like body and usually congregate along the tree's young branches, and can sometimes be scraped off if it's not too bad of an infestation. Otherwise, use insecticidal soap for them, too.
- Naval orangeworm caterpillars: Naval orangeworm caterpillars are the larvae of a moth and overwinter in the fallen debris and nuts under the tree. The small caterpillars are reddish-yellow in color and feed on the inside of the almond, which depletes the harvest. Control the problem by keeping all debris under the tree cleaned up, especially the fallen nuts.
- Tent caterpillars: Easily identifiable, tent caterpillars create a massive web especially in the crotch of the tree. The caterpillar eats away at the almond's foliage until skeletonized. If left untreated, a large infestation can defoliate the tree. In cases of small infestations, gardeners can pick the caterpillars from the plant and drop into a bucket of soapy water. When infestations are large, spraying the tree with Bt helps control the caterpillars. Repeat weekly.
- Peach tree borers: Peach tree borers are the larvae of a moth and bore into the tree's crotches and upper branches causing the tree to exude a gummy substance. The larva overwinters in debris under the tree and works their way up and into the bark when the weather warms. They tunnel inside the bark eating the inner tissue. The borers cause stunted growth weakening the tree and can kill young almond trees and severely stress older trees. Help prevent the problem by keeping the area under the tree clean of debris. Spraying the trunk with neem oil before the weather warms and reapplying twice monthly throughout summer, also keeps the borers under control.
A Bounty Worth the Extra Attention
Some may consider almond trees high-maintenance when it comes to their continued care, but their tasty and versatile harvest is worth the effort. With proper attention, you will enjoy your own fresh almonds for many years to come and have enough to share with the local wildlife and neighbors.