I grew up in Arizona, where I had no appreciation for the absurd quantities of spectacular citrus I had access to, usually in my own backyard. As an adult who lives far from the desert, I understand what I’m missing and spend trips back to Phoenix harassing friends to let me pick all their lemons and tangelos. If you grew up around citrus, you know that fall is when you do the work to ensure a plentiful and quality late-winter harvest. 

Most of the country can’t grow citrus outdoors, so if you’re like me, you bring citrus inside for the winter (“Oh, that’s my living room lemon”). But in locations like Florida and Arizona, where citrus not only thrives but constitutes a legitimate portion of the state’s economy, September kicks off citrus season. 

How much to water

You want to start slowing down your watering beginning now, to once a week, barring extreme heat events. When you water, this should not be a sprinkler or a light watering, but a deep watering where a slow drip is allowed to run for 30 minutes or more. 

Be on the lookout for leaf drop—more than a few leaves falling is a sign of not enough or too much water. Based on what changes you’ve made recently, you should be able to tell which is the problem. 

Should you fertilize?

September and October are the last time you want to fertilize for the year, and you definitely want to ensure your trees are fed well. Past that time, you don’t want the fertilizer to encourage new growth, since it will be susceptible to the winter temperatures. Even warm areas have a dormant period. 

You specifically want to look for citrus fertilizer, which will not be high in nitrogen, which encourages that new growth. 

Look out for pests and disease

Citrus has a number of pests to look for—aphids, scale insects, and citrus leafminers—and fall is when to spot them. For instance, citrus aphids aren’t white like other aphids you see around the garden, but brown.  If you see a problem emerging, treat it ASAP.

There are two methods of treatment: natural predators and insecticide. Introducing beneficial insects is a terrific way to help manage your trees, but where that fails, consult your local garden center for the right surface treatments. 

Yellowing leaves is a great indicator of a sick tree. Mold is another. If you see either of these, bring a sample to your local nursery for help diagnosing and treating your trees. 

Don’t prune (but do plant)

You never want to prune your citrus in fall. Spring and summer, after harvest, are appropriate times to do so. If you prune your citrus now, you leave exposed cuts susceptible to the winter cold. 

On the other hand, October is a fantastic time to plant new citrus, allowing your trees enough time to settle in before winter begins.

Paint trunks to prevent scalding

If you’re experiencing extreme heat, it’s a good idea to paint the trunk of your citrus with white tree paint to prevent scalding from the sun. 

Mulch now

Fall is the right time to set down a new layer of mulch, which, if applied correctly, will provide insulation for the tree roots. Insulation means less temperature and moisture fluctuation. However, you want to avoid the rookie mistake too many make of laying mulch right up to the tree trunk. This is a good way to spread disease—make sure to pull the mulch a foot away from the tree trunk. 

Consider insulation for your trees

If you live someplace experiencing more severe winters, which is happening even in the desert these days, additional insulation might be a good idea. You can wrap the trunk up, use frost blankets, or consider the very old, DIY solution of wrapping trees with older non-LED, incandescent holiday lights, which provide a little heat.