As our strawberry plants slowly start growing this winter it is time to make sure they have the fertility they need to give us the best crop. It is always good to get a tissue sample in mid to late January to determine if additional boron is needed in the plant.
Since we are past that point it is time to start working on getting nitrogen (N) to the crop. I like to recommend using a combination of potassium (K) nitrate and calcium (Ca) nitrate. We usually want to start off applying around 0.5 lbs. of N per acre per day or 3.5 lbs. of N per week. As we progress further into bloom you will increase fertility to 0.75 lb./A/day. Depending on the crop load you may eventually increase N fertility to 1 lb./A/day or 7 pounds of N per week
To monitor N levels in the plants throughout the season it is recommended that you begin taking petiole samples begininng with early bloom. Most labs are capable of running these tests. These samples help you determine the nitrate-nitrogen concentration in the plants which allows for better nitrogen fertilizer managment.
| Week | Low | High |
| 1 | 600 | 1500 |
| 2 – 3 | 4000 | 6000 |
| 4 | 3500 | 6000 |
| 5 – 8 | 300 | 5000 |
| 9 – 10 | 2000 | 4500 |
| 11 | 1500 | 3000 |
| 12 | 1000 | 2000 |
If you are on a sandy site fertilizer should be injected with every scheduled irrigation. If you have a heavier soil then you can fertilized less frequently. The key is to put the nutrients in the root zone for better availability.
Additionaly, petiole testing is probably warranted on newer varieties being grown around the state. We are well aware of different nutrient requirements but at this time do not have any good research to support this. Using petiole sampling on the farm could help individual growers tailor their fertilizer program to the current varieties grown, their soils and their markets.
