The best time to prune and clean up strawberry beds is right after harvest season is over. Where I live that can be as late as August. I ended up doing all my work on these beds in September, but we had a nice long summer here so the plants didn't seem to mind.
|Very messy strawberry bed!|
My strawberry beds have been experiencing problems with gray mold in the last two years. Gray mold is a fungal disease, and fungus' thrive when there is poor air circulation. Therefore it was important for me to take time to reduce the number of plants in the bed, cut back the foliage to reduce canopy cover, and clean up as much dead plant debris rotting in the bed as possible.
|lots of dead plant material to clean up|
To do this, I pruned each strawberry plant down to the crown- being careful not to damage the crown where new leaves were forming. If there were already full size new leaves I left them on the plant like in the picture above. I could tell new leaves from old based on a couple observations:
1. new leaves had shorter stems
2. new leaves seemed hairier.
3. color of new leaves was a lighter green.
If I had pruned right after harvest, there would have been less new leaves, and I could have pruned down to the crown like in this picture:
|strawberry plant pruned down to crown|
Pruning will stimulate new growth before winter which is important for next years' crop, but also allows you to evaluate the plants. You need to be able to dig up and transplant strawberries that are too close together, or remove plants that are too old. Older plants have longer stems. You can see this in the two pictures below. The top picture is a young plant, the bottom is an older plant.
|short stem of younger plant (brown part at bottom)|
|super long stem of older plant|
Older plants don't produce as well, and since strawberries create daughter plants by sending out runners every year, you can remove older plants without reducing the total number of plants in your bed if you keep the new plants.
Once I prune all the plants and remove old ones, I can transplant younger strawberries to my desired spacing of one plant every 6 inches, with 8 to 12 inches between the rows. This will allow me to harvest better next year because I will have less canopy cover and more defined rows. Less canopy also reduces disease problems by increasing air circulation.
Make sure you also get as much old plant debris cleaned out of the bed as possible, because disease-causing organisms can overwinter there. This is also the time to fertilize your plants, with an all-purpose organic fertilizer. I use fertilizer from Walt's Organic Fertilizer Company or Black Lake Organic. Adding a side band to each row will work just fine.
Good luck and happy renovating!