Marilyn J. Asked
When and what kind of fertilizer should I use for rhubarb and asparagus?
The Gardener’s Answer
Hello, Marilyn: As with any vegetable in the garden, a fertile/nutrient-rich soil is essential for a good crop. Asparagus will appreciate additional compost and fertilizer added to the soil at the time of planting. If this is your first year planting asparagus, you should go this route; otherwise you should side-dress your veggies with 1 pound of a slow-release fertilizer with a ratio of 5-10-10 per 100 square feet. After growth begins and once again during the growing season, you can add ammonium nitrate at a rate of 10 Tbs. for each 10 feet of planting row. As for rhubarb, if this is your first year growing, go ahead and incorporate some compost into the soil at planting time. You can also use a commercial fertilizer such as 16-8-8. Rhubarb has a high nitrogen requirement, so the first number in the fertilizer ratio should be the highest. Rhubarb can be fertilized three times per year: once at planting, again when the growth begins, and then after harvest to keep the soil rich. Rhubarb also responds well to manure. With any fertilizer you should try to work it into the top 6 inches of soil and water in. Side-dressing will work just fine as long as the soil is not compacted and it is allowed to work its way down into the soil. You may also consider having your soil tested through your County Cooperative Extension Service if you have not already done so.