Strawberry Next Steps

March 11, 2024

Many growers are now starting to think about how and when they should take the straw cover off their strawberries. With the warm temperatures that we have seen this winter, it no doubt seems tempting to take the straw off.

However, before you do that, you want to be educated about a few details. You want to understand when the ideal time is to uncover – not just from everyone else’s perspective, but in your specific context. This means that you first need to understand what your goals really are: Are you looking to push the harvest as early as possible, or just whenever it happens?

The first and most important part is to continually check the plants. Are they starting to green up – with a yellow-white shine? If so, then it is important to uncover them right away – they need sun. Leaving the straw on too long can be detrimental because the plants need light to photosynthesize and produce sugars and carbohydrates, which in turn are important for energy production and root growth.

There are also two critical temperature points that you need to be aware of:

• The first is the 20-degree rule: during the growth phase, you never want to see the air temperature, particularly around the crowns of the plants, drop beneath 20 degrees. If it does, you are at risk of getting crown damage. For this rule, you actually want to measure at the crown, not just using normal thermometer readings. Otherwise, you want to factor in several more degrees, since it is often 4-6 degrees colder down by the soil than what the thermometers show.
• The second is the 32-degree rule: during the bloom or fruit set phase, you never want to see the air temperature drop beneath 32 degrees. If it does, you are at risk of losing the blossoms and/or fruit.

Whatever your goals are, these two rules are important to keep in mind. They can help you make better decisions. For example, if you decide that you want an early harvest, you may want to take the straw off them right away. You may even want to cover them with floating row cover to get more heat to them during the day, which will wake them up faster. However, if you do that, you also need to keep in mind that you will then have blossoms and fruit set earlier, which will need to be protected if we get into the freezing zone. This will potentially require either multiple layers of floating row cover and/or misting the plants with water during these freeze events.

On the other hand, if you don’t have frost protection options, or if you are looking for a later harvest, you need to manage it differently. Even if you need to remove the straw because the plants are starting to grow, there is still more that you can do. Keep the plants uncovered whenever you can. If temperatures drop to the point where you need to cover up, do so. But remove the cover as soon as you can the next morning. In other words, you want to avoid letting the plants get too cold, but you also don’t want to push higher temperatures than absolutely necessary – which is why you uncover as soon as possible.

In summary, the key is to be keep a close eye on the weather and the strawberries. Then manage for these two rules to ensure that temperatures don’t drop too low.

Also, we expect to be following up later with another hotline on frost protection management options.