So you've planted or intend to plant a Eucalyptus tree in your landscape and you want to know how to fertilize and water it.
You'll be happy to know that Eucalyptus trees do NOT require feeding. Reason being, in their native environment of Australia and Tasmania, Eucalyptus trees grow in very well-drained grevelly soil that is often very shallow over bedrock. These conditions forced Eucalyptus to adapt to growing in soils where thee are little to no nutrients.
So, feeding Eucalyptus isn't important, however soil pH is important. Soil pH is a measurement of the acidity or alkalinity of your soil. It is determined by the amount of lime (calcium) contained in your soil, and the type of soil you have. Why is this important? Nutrients for plant growth are "bound" within the soil. In the case of Eucalyptus, they prefer an acid pH of 5.5 to 6.4. If your soil pH goes above 7.0 on the pH scale, nutrients like iron are "locked up" and are not available to plants. Regarding Eucalyptus, if you see yellowing leaves that have green veins, suspect improper pH first. and take steps to correct it, which usually means an application of soil sulfur or some other element that helps to make soil more acod or limestone to make the soil more alkaline.
You can test your soil pH with a soil test kit found at many nursery and garden centers, or you can buy a soil test kit online here.
How To Water A Eucalyptus Tree
How much water a Eucalyptus tree will require will depend on several different factors: the variety, local climate conditions, soil type and drainage, and rainfall amounts.
Average rainfall ranges in most areas of the world range from just a few inches per year, upwards of 100 inches or more. Think desert climate verses tropical rainforest. If the variety of Eucalyptus originated in desert environment it will have adapted to low water needs and tropical rainforest plants need to humidity and moist soils.
Eucalyptus can be found growing in the wild somewhere in-between the high and low rainfall amlounts. For example, Eucalyptus striaticaly thrives nicely with only about 6" of rainfall per year, where Corymbia gummifera needs 27-70 inches of rainfall per year. So know the needs of the varieties of Eucalyptus you are growing.
If you intend to grow a rainforest type Eucalyptus in a desert climate supplemental watering will be required to sustain health of the plant. If you intend to grow a desert Eucalyptus species in a tropical rainforest well, good luck with that one. It's much easier to provide additional water but you can't take the moisture out of the air and soil in a rainforest.
So, when selecting a Eucalyptus species to grow in your landscape, make sure it's one that will like your climate and average rainfall amounts. Simply put, do your research. With so many species and varieties available, it's impossible to list them all here along with their water requirements. So do a Google search on specific varieties you might want to try to find out their water needs. For example, you can type something like this into the search: "Equalyptus nicholii water needs," or "Eucalyptus nicholli moisture needs."
For those of you who live in U*SDA Zones 6a-10b, you can buy cold hardy Eucalyptus trees online from Gardener Direct Nursery
