I recently decided to plant several citrus and avocado trees around the perimeter of my backyard. I knew that I was going to be placing the trees a lot closer than what is recommended because we are going for a hedge and privacy screen along the yard.
My soil is clay, but I really do not have much of a drainage issue, especially where the tree will be located. I tested the clay soil and the water drained well. One other advantage I have at this location is a 6-10 foot steep slope less than 5 feet from where they will be planted. This will help with drainage as excess water will run off rather than be allowed to form a puddle or pool.
I did a lot of research on planting these trees in my area of southern California and here is the best information I could find, although I did not follow all of it.
Climate Needed For Citrus Trees
In parts of North America (zones 8-11, some varieties are only cold tolerant to zone 9) where citrus is grown outside, early spring is the best time to plant citrus trees. It will give the plant a bit of cool weather through spring to adjust from transplant shock and the whole summer to grow new roots and foliage. While. in southern California, parts of Arizona and Texas, and Florida are referred to as the “citrus belt”, trees can be planted during any time of the year with adequate care.
Citrus trees planted in containers indoors can be planted in any zone and at any time of the year.
Best Planting Site for Citrus Trees
Citrus trees love the warmth and lots of sun. So, select a location that receives at least 6 hours of sun per day, more is always better. The more sun the citrus tree receives the sweeter the fruit. Citrus trees like limes, lemons, and grapefruits, where sweetness isn’t the greatest concern. So, over 6 hours of direct sunshine per day is less of a concern.
Citrus trees perform best in well-drained soil like sandy loam. Soil that does not drain well and allows water to sit around the root system, citrus trees will suffer from root rot. If you have clay-type soil it is best to test the drainage of your soil. If water does not drain fast enough you should plant the tree on a mound.
Citrus trees prefer the soil to be slightly acidic. So, it is recommended that you test the PH of the soil and adjust PH to be 6.0-7.0, which is ideal for citrus trees.
Dwarf citrus trees should be spaced as close as 6 to 10 feet apart, Semi-dwarf varieties can be spaced 10 to 15 feet apart while standard-size citrus trees will need to be spaced 12 to 25 feet apart. Trees that are spaced closer will experience crowding and will require additional pruning. Occasionally, you will see citrus trees planted close together to create a hedge. The biggest disadvantage of planting a citrus hedge will be less fruit production.
Planting Citrus Trees in Clay Soil
Planting citrus trees in clay soil is more changing but can be done successfully with a little extra work at planting.
The soil will need to be tested for drainage. The test is pretty simple, you simply dig a hole about 1 foot deep and 1 foot in diameter. Fill the hole with water and see if it drains in 12 hours. If not then the soil is not acceptable for citrus. But there are ways to make it work
One option is to amend the soil in an area about the size of the mature tree’s dripline. The soil will need to be amended with 4 inches of organic material ( manure, compost, or a commercial soil conditioner) to a depth of 16 inches. For most individuals, this may not be an option because the difficulty in getting to a depth of 16 inches would require a lot of work or special equipment. There is a simpler solution.
The tree can also be planted on a mound. For best drainage, the mound should be at least as high as the root ball of the citrus tree and taper down from the base of the trunk. The mound should be a minimum of 3 feet in width. The soil can be a mix of native soil or a mix of native soil and compost. The raised mound will assure adequate drainage and keep the roots at the base of the tree from becoming waterlogged and rot, eventually killing the tree.
Planting a Citrus Trees
- Use care when removing your tree from its container. It is best to use a sharp razor knife and cut the container from the root ball. If the tree is root-bound (roots growing in a spiral pattern in the pot) use the knife to score the roots on 4 sides with a razor knife. This will promote the rots to start growing outward rather than continue to grow in a circular pattern.
- Dig a hole that’s about 1.5 times the width of the current root system and only as deep. Digging deeper will create a bowl where water may accumulate and cause root rot.
- When planting a citrus tree always plant it a bit above the surrounding soil and keep the trunk at the highest point. This will prevent water from pooling around the trunk and causing disease or rot.
- In clay soils where water does not drain well. It is best to place the root ball at or above the surface of the ground and mound dirt around the root ball to prevent root rot. This mound should be at least as high as the current root ball and 4 to 6 feet wide. The mound should taper down from the trunk and the base of the tree should be the highest point in the mound.
- Note: Almost all citrus is grafted, and care should be taken to keep the graft area at least 4 inches above the soil. If the graft gets too close to the ground the grafted part of the tree could grow roots and alter the size of the tree. This is especially true with dwarf and semi-dwarf trees.
- Place the tree into the hole and backfill around the root ball with native soil. After the hole is about half-filled with soil, wet around the root ball with water to settle the soil and remove air pockets. Once the water has soaked in, fill the rest of the hole with more native soil. After the hole is filled, completely soak the area around the root ball. This will finish settling the soil and removing air pockets in the soil.
- Tip: It is highly advised not to amend the soil around the new trees. It is best to use the native soil so the tree can quickly acclimate to its new soil.
How to Care for Citrus Trees
- Citrus trees have shallow roots that grow across the surface of the soil. I light covering of mulch, no more than 3 inches thick helps to protect these roots in a layer of organic matter. When using mulch, organic wood chips, pine straw, compost, or lawn clippings are all suitable materials. One drawback of using mulch is the potential for the soil to retain too much water and reduce airflow. So you should keep mulch back 12 inches from the base of the trunk.
- A fertilized like 10-10-10 that is formulated for trees can be used to encourage growth and fruiting. There are fertilizers available that are specialized for citrus trees are worth looking into.
- You should not plant ground cover around the base of citrus trees. Ground covers will compete with the shallow roots of the citrus trees for nutrients. You will likely damage the roots of an established citrus tree attempting to plant them.
- Citrus trees do not require fruit thinning, because they typically experience what is something called “June drop.” In late May or June, the trees will drop immature fruit that the tree will not be able to support to maturity. This allows the remaining fruit to get enough nutrients from the tree to grow and ripen properly.