“How often should I water with drippers my 20-year-old Santa Rosa plum tree?” Question from Gloria of Morgan Hill, California

Answer: Even established trees with deep roots need supplemental water during dry spells. In arid areas where soils are poor, irrigation is even more important, as is fertilization. Let rainfall decide when you irrigate your Santa Rosa plum tree (Prunus salicina ‘Santa Rosa’). During extra dry periods, you may need to water it two to three times a month. Remember that tree roots flare out, and most feeder roots are along the periphery of the flare, so avoid just watering near the trunk. The flare often follows a tree’s branching, so water further out to really irrigate properly.

Plum trees grow best in fertile soils that drain well. Adding a layer of compost, such as Black Gold Garden Compost Blend around the roots each year can help slowly feed the soil and hold in needed moisture.

Happy gardening!

Jessie Keith

Black Gold Horticulturist