How and When to Thin a Strawberry Bed

Perhaps you planted a few strawberry plants last year, and now they’re out of control. Or maybe you inherited an old strawberry bed when you purchased a new house. Regardless, you’re wondering how to transform that unruly jungle of a strawberry bed into the neat, berry-producing patch you’ve dreamed of.

Proper thinning is one key part of maintaining a healthy and productive bed. This process involves removing old and unproductive crowns to allow younger plants to flourish. Stay with me to learn everything you need to know about successfully pruning strawberry plants.

Understanding How Strawberry Plants Grow

Before I cover the details regarding the process of renovating strawberry beds, I’ll explain how strawberry plants grow. After all, you can’t tinker with something if you don’t understand all the parts!

Strawberry plants are herbaceous perennials that form thickened stems known as crowns. Roots, leaves, fruits, and aboveground runners all emerge from the crown. Eventually, the sprawling runners form small “daughter” plants. These plants then root into the soil, form a new crown, and begin to grow into mature plants that send out their own runners.

When you consider that each plant can send out many daughter plants, and each daughter plant can produce its own offspring, it’s easy to imagine how a strawberry bed can become overgrown in just one season.

Should I Thin Out My Strawberry Bed?

The short answer is yes! While your strawberry plants will grow and produce fruit if you forgo thinning, spending a few hours renovating your beds each year provides the following benefits. 

Increase Fruit Production

Most strawberry plants are the most productive in their second and third year of growth. While they may continue to send out a few berries in years four and five, you’ll notice your harvest basket becoming less and less full.

However, you don’t have to plant new plants every few years to keep your strawberry patch pumping out sweet, juicy berries!

Thinning involves removing old plants and leaving room for new plants to expand. With more room to grow, daughter plants mature and begin producing fruit. And by the time these plants’ fruit production fades, new daughter plants will be ready to step up to the plate as fruit producers.

Thinning also ensures that each plant can access the water, light, and nutrients it needs to produce fruit. While it’s easy to think more plants are better, a handful of healthy plants are far more productive than a boatload of mediocre plants.

Improve Disease Resistance

Thinning also helps limit the development and spread of common strawberry diseases. When strawberry plants are allowed to their own devices, they will quickly grow into a dense mat.

These tightly packed plants mean limited airflow and increased moisture under the plants’ canopy, both of which increase the likelihood of fungal diseases like leaf scorch and gray mold.

Thinning out extra plants improves airflow and helps keep these diseases at bay.

Save Money

Although strawberries are perennial plants, some people choose to replant them each year. That’s because individual plants are the most productive in their second year of growth. While this method results in a reliably productive harvest each year, it involves purchasing and planting new strawberries each year.

Thinning your strawberry bed allows you to keep the new plants the bed naturally produces and avoid purchasing new plants. You will have to spend some time pruning, but not any more time than you would removing old strawberry plants and replanting new ones. Plus, you don’t have to spend money on new plants.

When Is the Best Time to Thin Strawberries?

Late summer or early fall is the best time to thin both June-bearing and everbearing strawberry plants. At this point, the plants are done producing fruits, and their vegetative growth has slowed for the season. Thinning the plants in the fall allows you to enjoy a healthy and productive bed the following spring.

While you should complete the major pruning event after the plants finish producing fruits, you can also complete light pruning throughout the summer if you notice plants are becoming overcrowded.

How to Prune a Strawberry Bed During the Growing Season

Depending on where you live, you should plant strawberries in either the fall or early spring. Although you can plant strawberries in containers, growing them in the ground is a popular method. If you choose to plant them in a bed, leave 15-18 inches between plants and three to four feet between each row. Keep this spacing in mind for future pruning.

Regardless of when you add the plants to the ground, they’ll begin putting on new growth by the late spring. If you’re growing plants in rows, it’s okay for the runners to fill in the space between the initial plants. However, removing the runners that sprawl between each row of plants makes harvesting easier. You can remove each runner by pulling them up by hand or cutting them off with a pair of pruning shears.

You can also trim off some of the leaves if you notice they’re becoming overcrowded or diseased. This will help keep the plants healthy and decrease the chances of disease.

How to Renovate a Strawberry Bed

You know how contractors take an old kitchen, remove the outdated tile, touch up the cabinets, and end up with a room that looks almost brand new? Well, you can transform your outdated and overgrown strawberry beds in a similar manner. That’s why the act of taking an overcrowded strawberry bed and converting it into something more neat and tidy is known as renovating.

Thinning is just one part of the overall renovation process. Other steps include mowing, removing weeds, fertilizing, and potentially mulching. Follow these steps to breathe new life into your strawberry bed.

Wait Until the Right Time of the Year

The late summer or early fall is the best time to thoroughly overhaul a strawberry bed. At this point, the plants are done producing fruit, but they’ll have time to recover before cold weather arrives. You can renovate June-bearing fruits in midsummer, but there’s no harm in waiting until the early fall.

Remove Weeds

Check for any mature weeds in and around your strawberry beds. Remove the weeds and place them in your compost pile or somewhere else away from the beds. Make sure to dig out the roots of perennial plants like thistle and dandelions.

Mow the Tops of the Plants

Although mowing is optional, it’s a recommended step in the broader renovation process. Removing so much of the plants may seem harmful, but getting rid of old growth allows for healthy, new growth to flourish.

The goal is to cut the foliage two to three inches above the plants’ crowns. One way to do this is to set a lawnmower to the highest setting and carefully mow over the plants. Just make sure to test the mower on a small patch before running over your entire bed!

A few other options include trimming the tops of the plants with a weed whacker or cutting the leaves off with a pair of pruning shears. Whatever option you choose, be careful to leave the crowns intact since they produce new growth.

Thin the Rows

If you’ve planted your strawberry plants in rows, your first step is removing any runners and plants that have grown into the space between the rows. You can do this by tilling the plant with a small rototiller or disturbing the ground with a hoe.

When you’re done, each row of strawberry plants should be 12-18 inches wide. Don’t worry about this step if your strawberries are growing in a patch rather than rows.

Thin Out Old Crowns

Your next task is to remove old crowns to make room for new crowns to grow. Older crowns are larger than newer ones and may have brown or otherwise discolored pieces. Aim to thin the plants so they’re 12-18 inches apart.

Insert a small hand trowel below the plants you want to remove, then pull the trowel upward until the crowns pop out of the ground. After thinning, remove any runners emerging from the remaining crowns.

Fertilize and Mulch

Once your strawberry beds are looking neat again, it’s time to fertilize the plants for the following growing season. Choose a balanced, granular fertilizer with an NPK ratio of 10-10-10 or 12-12-12. Follow product instructions and sprinkle the fertilizer in the strawberry bed.

Mulching your beds is optional, but it helps the soil maintain moisture and keeps berries off the ground, limiting disease and insect damage. Apply a light layer of straw, woodchips, or leaves on the bare soil around the plants.