Fertilizer for strawberries replenishes nitrogen, phosphorus, and potassium in the soil. Whether you're an organic gardener or choose conventional methods to grow berries, there are many choices of fertilizer.
Out of all the fruit one can grow in the garden, strawberries are perhaps the best-loved. The ripe, juicy, sweet red fruits are the harbingers of summer. Strawberries can be grown in almost all gardening zones, and even a few plants can yield tasty berries in their first year.
How Strawberries Grow
To understand how to fertilize strawberries, it helps to understand how strawberries grow. All strawberry plants are generally shallow-rooted. This means that the plant doesn't put down deep roots. Because the roots grow near the surface, the plants tend to use up the nutrients near the top of the soil very quickly. Unlike a tree, which can send its roots deep into the ground to find additional nutrients, strawberries are stuck with what's available to them.
How to Tell When Strawberries Need Fertilizer
Plants display several clues when they need fertilizer. Learn how to read your strawberry plants' signals correctly. Some of these clues may also point toward insects or other problems, so be sure to consult a local gardener or someone at your local garden center if your plants continue to struggle.
- Pale or yellow-colored leaves: This may indicate a strawberry plant needs fertilizer.
- No berries: Plants may produce flowers, but berries either fail to develop or never develop at all.
- No flowers: The plants look green and healthy, but never flower.
Types of Fertilizer for Strawberries
There are several fertilizer choices that are great for strawberries. You may find that some types are more effective than others, depending on the fertility of your native soil, as well as other growing conditions.
Compost is a rich, natural fertilizer that strawberries love. Compost is an organic fertilizer and soil amendment made by nature decomposing leaves, grass clippings, and other plant material. You can add shredded newspaper, discarded outer leaves of lettuce, apple peels, and any other vegetable material from the kitchen into the compost pile.
Over time, heat and moisture encourage microbes to break down the plant material, and worms chewing their way through the pile leave behind casings, or droppings, that add rich material to the soil. Compost is an excellent all-around soil amendment and is recommended for nearly every garden.
Whether you make your own compost or buy it bagged at the store, add a layer of compost about one to two inches thick to the soil before planting strawberries.
Commercial Fertilizers for Strawberries
Commercial fertilizers contain a chemical blend of nitrogen, phosphorus, and potassium, along with some trace minerals. Fertilizer bags list these elements as numbers in a ratio such as "5-10-5" and "10-10-10." The numbers reflect the percent for each element, with nitrogen always the first number, phosphorus the second, and potassium the third.
- If choosing a commercial fertilizer for strawberries, look for a balanced fertilizer. A balanced fertilizer will show all numbers as the same, like 5-5-5 or 10-10-10. The safest fertilizer for strawberries is a 10-10-10.
- Use about two and a half pounds of 10-10-10 fertilizer for every 100-foot row of strawberries.
- Broadcast or sprinkle the fertilizer around the plants and follow the package directions.
When to Fertilize Strawberries
Knowing when to fertilize strawberries is key to getting a good harvest. For best results, fertilize strawberries in early spring, and then again in fall.
For newly-planted strawberries, you'll know that you need to fertilize if the leaves on the strawberry plants turn yellow within a month of planting them in the garden. If you notice that yellowing, apply a 10-10-10 fertilizer. If you're growing strawberries in pots, you'll want to fertilize monthly.
Getting a soil test done at your local county cooperative extension office is a great idea to ensure that you're neither over-fertilizing nor under-fertilizing your strawberry plants.
Grow the Best, Juiciest Strawberries
In addition to choosing the best types of strawberries for your garden and needs, planting them properly, and fertilizing as described above, you'll also want to be sure to mulch the area well. The shallow roots of strawberries dry out quickly in hot, dry weather, and that can affect the fruit. By keeping these tips in mind, you'll be well on your way to a perfect strawberry harvest.