Best Growing Conditions for a Eucalyptus Tree
Sun - For best growth rates and fuller trees, Eucalytpus trees prefer full to mostly sun. That being said, some varieties will do okay in dappled shade. Overall, the more sun the better.
Soil Type Preferred - Eucalyptus trees adapt to most soil types provided there is good drainage. Constantly wet soil can be a killer. In soil with low fertility or compact clay it'll be worth your time to mix in some organic compost to the native soil.
Soil pH Preferred - Eucalyptus trees do best in a slightly acidic soil ranging between 6.0 to 6.6 on the pH scale. Whenever growing plants that prefer a specific pH it's a good idea to test the soil. Testing kits are available at most local nursery and garden centers or you can buy soil test kits online here. Your local Extension Service might provide soil testing services as well. Depending on the results of the soil test, you can add lime to raise the pH or soil sulfur to lower the pH (make more acid).
How To Plant A Eucalyptus Tree
Below are general guidelines for properly planting a container-grown Eucalyptus tree in most average garden soils.
STEP 1 - Begin by digging a hole at least twice as wide and a little deeper than the rootball is tall. Place the native soil removed from the planting hole around the perimeter of the hole.
STEP 2 - Depending on the fertility and porosity of the soil you are planting in, you might need to add a soil amendment to the native soil removed from the planting hole. When planting in heavy clay soil, it's a good idea to thoroughly mix in some good organic matter such as composted cow manure, mushroom compost, or a good planting mix at a 25 to 50% ratio with the clay soil. When planting in very sandy, quick-draining soil you might want to consider adding in some peat moss and or compost to help retain moisture. When planting in fertile, well-draining soil there's no need to add any soil amendment.
STEP 3 - To remove your Eucalyptus tree from the container it was growing in, firmly grasp the base of the trunk and gently try to lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and gently pound on the side of the container to loosen the root ball. After having removed the plant from the container it is not necessary to loosen any roots. There’s no need to spread out the roots while planting, as this could damage their sensitive root system.
STEP 4 - Place tree in hole making sure that the top edge of the root ball is at or slightly above ground level. If necessary, place additional soil in the bottom of the planting hole to achieve proper planting height. Then start pulling your backfill soil mixture into the hole around the rootball tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue back-filling to the top edge of the root ball, tapering your soil mixture gradually to the ground level. Do not put any backfill soil on top of the root ball as doing so can suffocate your tree.
STEP 5 - With remaining soil mixture, or additional native top soil, you can build a water retaining ring around the perimeter of the planting hole to a height of around 2 to 6 inches or so, depending on the size of the tree and it's relative water needs.
STEP 6 - After planting, fill water retension area with water and allow to soak in. Repeat this process one or two more times. Therafter, water as needed to maintain a moist but not wet soil.
STEP 7 - To retain adequate moisture, apply a 2-inch layer of shredded wood mulch, or a 3-inch layer of pinestraw to a distance of 2-3 feet from trunk of tree, or just beyond water retaining ring.
For those of you who live in USDA Zones 6a-10b, you can buy cold hardy Eucalyptus trees online from Gardener Direct Nursery
