Mulching the soil under the crown of a tree, as soon as the soil thaws or a little later, while the soil is moist, is the primary agricultural practice not only for maintaining moisture in the soil, but also the main condition for the good development of beneficial microflora and microfauna, and especially earthworms. Earthworms not only create soil humus, but roots grow well along the paths of earthworms, water and air pass through, and when dying off, the worms themselves become a good food for the roots of fruit trees.
It is necessary to mulch (fill) with a layer of 10-15 cm, preferably with rotted (with earthworms) or semi-rotted manure or compost. If this is not the case, then you can mulch with grass, straw, hay, leaves, but not sawdust, which greatly acidifies the soil and takes nitrogen away from it, so the sawdust must be used for composting.
On old trees, in addition to mulching, it is also good to make deep fertilizing with organic fertilizers, for which you need to dig 4-8 pits around the crown perimeter 50x50x50cm in size and lay well-rotted (with earthworms) manure or compost in them. As it decays and subsides, manure must also be added to the soil level. Such pits should be watered abundantly and regularly. All this will contribute to the rejuvenation of the old root system of the tree, its good nutrition and the rapid restoration of frozen trees.
Top dressing with mineral fertilizers in May-June is not necessary, since they increase the concentration of the soil solution, which makes it difficult for it to move from roots to leaves along frozen wood vessels.
With regard to the actual watering itself, you need to know that it must be ABUNISHING so that the soil under the crown of the tree is well moist throughout the entire root layer (up to 50-60 cm), not frequent, but regular as needed. If the soil is not mulched, then the soil crust formed after irrigation must be destroyed by hoeing so that the water does not evaporate through the capillaries.
Gardeners need to know that the main attention for good care (pruning, mulching, watering, combating diseases and pests, weeds, etc.) for fruit trees should be paid at the beginning of the growing season (May-June), so that the tree forms a powerful a canopy of healthy (not damaged by diseases and pests, dark green, dense) leaves, which is the key to good growth, fruiting, restoration of frozen trees, their high winter hardiness and longevity.