Question
Hi!
I live in San Francisco bay area and i bought watermelon (sugar baby) plants from the nursery about 2 months ago.  the plants are doing well, spreading out quickly but the fruits are so tiny (just about 1"in in dia) I was told the watermelon will mature in 70 days. it has been 60 days now and the fruit are still very very small.
I give enough water and some chicken manure fertilizer at the beginning. am i doing something wrong?
thank you
min

Answer
You are not necessarily doing anything wrong. It sounds like you're watering regularly and the chicken manure is acting as a slow release fertilizer. However, keep in mind that chicken manure is very high in nitrogen. Nitrogen promotes lush foliage, which in turn takes away from the size of the fruit. Watermelon, like all fruit-producing plants, require a high amount of phosphorus. A good fertilizer ratio is 5-20-20, with the first number representing nitrogen, the second phosphorus, and the third potassium for root development.

This fall, I would add the chicken manure, and next spring I would add peat and compost prior to planting the watermelon. Once the plants start producing flowers, supplement their feeding with a fertilizer high in phosphorus. That should take care of the problem.

Enjoy the rest of your summer.

Mike