Position – The Santa Rosa plum tree needs full sun; at least 6 hours of unfiltered sunlight every day. Choose a site that is sheltered from strong winds. They are self-fertilising, so they will produce fruit even if there isn’t another tree nearby.
Size – At maturity, this tree will be between 5.5 and 6 metres tall with a spread of 3.5 to 4.5 metres. So, ensure that your tree is in a spot where it has the room to grow and extend its roots and canopy out.
Soil Type – Loamy, well-draining soil creates the ideal environment for the roots to get enough water without being waterlogged. The ground should be slightly acidic (ideally between 5.5 and 6.5).
Watering – Keep the soil around the tree’s root ball moist, but not soggy or flooded. At first, this will mean watering the ground around the young tree. As it matures, it may be wise to water it deeply, but less frequently. It’s a good idea to dig into the soil to see how far down the water is penetrating.
Fertilising – When your tree is young, use a nitrogen fertiliser in summer, spring and autumn. A mature Santa Rosa plum tree will benefit more from a fertiliser that is specifically designed for fruit trees. Just Berry Plants will be able to advise on fertilisers.
Mulch – Use organic mulch like compost, straw, crushed dried leaves or wood chips around the tree (keeping it about 20 centimetres away from the trunk). Mulch helps to retain the moisture in the soil, prevent the roots from being damaged by the sun, and keep nasty weeds at bay.
Pruning – Pruning your tree will encourage it to produce more fruit. Wait until the tree is dormant and all its leaves are off before pruning it. Remove dead or diseased limbs and keep 4 to 6 healthy limbs as your main scaffold. These limbs should be about 45° from the trunk and evenly distributed around it, if possible. If your Santa Rosa plum is growing very fast, consider thinning it out again in summer.
Harvesting – Your tree should begin to produce fruit when it is about 3 to 5 years old. The plums are ready to be picked when their skin is a beautiful red colour and they pull away easily from the tree.