here in nor cal, when we put our plants out in late march-early april, their roots are able to develop strong tap roots due to the couple of rains we get through march and april. This year i grew twenty plants near a creek 10 grandaddy purples 8 super silver hazes and 2 romberry. These plants are inaccessible and i have not watered a single time all year and my plants are the biggest plants ive ever seen in my life and as big as any ive ever seen on camera. Point is, if you plant early when the ground is not dry, preferably next to a water source roots will grow down deep and form a tap which will feed the plant all year long. If you plant normal cal. plant time i.e. june july you will probably have to water two or three times per month or more because the ground will be dry and the roots will find it difficult to penetrate.