How and when to fertilize olive trees – for healthy evergreen growth and a bumper harvest of fruits year after year

I’ve grown and cared for olive trees in all kinds of places while working as a professional gardener. I once looked after two lovely old and gnarled specimens in a front garden in Islington, North London. Even in this challenging concrete environment, they thrived.

However, while they are tough and resilient trees, I have found that olives can benefit from an occasional feed, especially when container-grown. They won’t mind poor soil, but that doesn’t mean they thrive on total neglect, so applying the right fertilizer at the right time will pay dividends.

So, whether your olive tree is old and sculptural in a large pot by the back door, or young and finding its feet in the border, feeding is a good job to add to your to-do list. Here’s everything I know about how to fertilize olive trees to keep them healthy and looking good.

Is it necessary to fertilize olive trees?

Technically, no, many olive trees don’t need much fertilizing, especially when planted in the ground. In the Mediterranean, they can thrive in poor, stony and sandy soil, without much need for supplemental feed.

That said, if you’re growing olive trees in pots, a little feed can really help. In particular, young trees often benefit from a top-up while establishing, and any olive grown in a container will be entirely reliant on you for nutrients.

When to feed olive trees

Timing is key when it comes to fertilizing fruit trees. If you are landscaping with olive trees and growing them in the ground, I would recommend feeding just once, in early spring. March or April is fine, usually with a slow-release general fertilizer. That one hit is often enough to support steady growth through spring and summer.

Potted fruit trees, though, need a bit more from you. I start feeding container olives once the weather warms up, usually around May time, feeding every two to three weeks until late summer.

Feeding any later than this would be a fertilizing mistake. The last thing you want is encouraging soft, sappy growth that will be struck by the first early frost.

How to feed olive trees

For trees in the ground, I usually use a granular fertilizer for all-around plant health. Something like blood, fish and bone will do the job. Scatter a handful or two around the base in spring, covering with a thin layer of mulch.

Use something like this organic bone meal by Espoma, available via Walmart.

Potted olives are another story. I would suggest using either a feed that is intended for olive trees or an organic fruit tree fertilizer available from Walmart. But any balanced liquid feed you have in the garden shed will have a similar result.

If your tree’s looking worse for wear in the spring – lacking verdancy or showing stunted growth – it might benefit from an early-season boost with a seaweed-based tonic.

Try this organic seaweed feed, available now via Amazon. Follow the recommended instructions found on the packaging of the feed, typically applying once or twice per season. With any luck, the nitrogen boost will help with foliage growth.

FAQs

Can I use tomato feed for olive trees?

Yes, tomato feed is a good product to use when you want to fertilize olive trees, particularly as this will help with flower and fruit production. It can help to use this alongside your other all-around feed. Use something like this tomato fertilizer from Walmart, diluting it in a watering can, feeding once in May and then again in July. I would suggest diluting it even more so than is recommended on the packaging to avoid damaging these tough, resilient trees.

In addition, a light fall or winter mulching will also help to nourish your plants. I like using well-rotted bark. Just be sure to keep it a few inches away from the trunk to prevent rot.

And, remember that while olive trees are drought-tolerant, it is a good idea to be deep-watering them in pots throughout the summer. If you tree suffers from heat stress and lack of water, no amount of feed will be able to save a dying olive.

Shop fertilizing accessories