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How To Fertilize Strawberry Plants – And When To Do It For A Big Harvest!

When and how you fertilize your strawberry plants can play a critical role in just how healthy your plants grow, and of course, how many strawberries they produce.

Whether you grow perennial everbearing or June bearing strawberries, the soil they grow in year in and year out will eventually lose its power. Like most vegetable and fruit bearing plants, strawberries require a good amount of Nitrogen, Phosphorous and Potassium (N-P-K) to produce healthy foliage and blooms.

In addition to the Big 3 of N-P-K, strawberries also require a fair amount of micro-nutrients to power growth. Unfortunately, unlike annual vegetable plants and flowers, you can’t rotate your berry plants to a new space each season. Because of that, with each passing year, without help, the soil becomes less fertile and your plants less productive.

when and how to fertilize strawberries
Whether you have existing strawberry plants or are planting new ones, when and how you fertilize can play a big role in how they perform.

The easiest and best way to fix this issue of course is with fertilizer. But when it comes to strawberry plants, when and how you apply that fertilizer can make a huge difference for your plants. Not just in their ability to produce more berries, but to be able to survive and overwinter with each passing year.

When & How To Fertilize Strawberry Plants

The When

There are two critical times that strawberry plants need to be fertilized. The first is early in the growing season before they ever begin to produce foliage or their berries. The second is in mid summer to early fall, before they begin to go dormant for the winter.

When it comes to early season fertilizing, you need to supply a dose of power to plants just before or right as they are coming out of their dormant stage. It is extremely important to apply the dose in the spring at the right time.

In early spring, the plants are ready to begin storing power in their root systems for fruit production. And when applied just as they start to grow, the nutrients are absorbed for better fruiting.

However, if you fertilize once the foliage has come out in full force, the nutrients instead will go more towards leaf growth than production. The end result will be big plants with little fruit!

early spring growth
Strawberry plants need to be fertilized early. Either right before they come out of dormancy, or in the first week or so after they begin to green up.

Never fertilize your crop when it is fruiting. It may seem like a good idea to give plants nutrients as they produce, but the energy can actually cause the plants to stop bloom production to concentrate on foliage growth.

If you are planting new strawberry plants in the spring, use compost in the planting hole in place of fertilizer. The compost will help roots feed slowly and spread easily. Unfortunately, giving them too much fertilizer can again cause plants to simply produce large foliage.

What To Fertilize With In The Spring – How To Fertilize Strawberry Plants

When fertilizing early in the season, a slow-release granular fertilizer is the way to go. With little foliage growing early in the season, a granular application will slowly soak to the roots below.

When selecting your fertilizer, look for one with either a balanced makeup of N-P-K, or one leaning to the potassium K) side a bit. One thing you want to avoid is any fertilizer that is heavier on the Nitrogen number. An excess of nitrogen will lead to more leaf growth and less fruit production.

Listen in to our Podcast on Growing Strawberries below!

Look for fertilizers that are near the 10-10-10 range when it comes to N-P-K. If you can, try to find a mix that actually has a bit higher number for the Potassium (K). Potassium aids greatly in fruit production and is excellent for helping to grow more plentiful and larger berries. Product Affiliate Link: Performance Organics Edibles Plant Nutrition Granules

More than anything else, be sure to fertilize early. Apply the fertilizer using the recommended rate on the back of your package. It is best to water the fertilizer in a bit to help it absorb into the soil.

As an alternative to granular fertilizers, you can use compost as a spring fertilizer. To apply, simply mulch around your plants with a few inches of compost and water in. Much as with the granular fertilizers, the nutrients will slowly soak in to help power the roots.

Fertilizing In Mid-Summer To Early Fall – How To Fertilize Strawberry Plants

Beyond the initial early spring fertilizing time period, it is also extremely important to power your crop once again in late summer to early fall. This application needs to take place after your plants have completed their fruiting cycle.

For fertilizing strawberries, select a fertilizer that is either balanced or slightly higher in potassium. Potassium will always be the third number in the N-P-K ratio, and helps to promote better fruit production and not just foliage growth.

For June bearing plants, fertilize in late summer after they have been pruned back. This will help them to regrow and recharge their root systems as well. Not only are strong roots important for good production, but healthy root structures are far less likely to freeze or die out through harsh winters.

If you are growing everbearing varieties of strawberries, it is best to apply a fertilizer in early fall as the plant starts to cease production. This will help it begin to store energy as well for the following year’s fruit.

No matter which type you grow, you can again use a good all purpose granular fertilizer or a few inches of compost to power your plants late in the season. One thing you don’t want to do is fertilize too late into fall. Fertilizing late can actually spur tender late growth, which leaves plants susceptible to winter damage.

Mulching – How To Fertilize Strawberry Plants

Once your strawberry crop begins to die back in late fall, it is time to put them to bed properly before winter. For this, mulching plants for both weed and winter protection is a must. Straw or shredded leaves are both excellent materials for this task. A three to four inch coating is more than enough to help plants take on winter.

For more on that topic, be sure to check out our article What To Do With Your Strawberries Before Winter. Here is to fertilizing your strawberry crop for big success this year, and for years to come!

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