Your fertilising programme needs to continue while you keep an eye out on the weather, as you must not fertilise if the soil is bone dry. Water first so that the soil is wet otherwise you could burn the roots. Heavy rain can also wash all the fertilisers out of the soil.
Pines will need far less fertiliser now than deciduous varieties, while fruiting trees require high in phosphorous fertilisers. Pines and Azaleas like a feed of Sequestrene. Soils will dry out in strong sun and even more so with strong warm winds, so you will need to water accordingly. If you have willow trees is an ideal time to set these in a tray that will hold shallow water as they do not like to dry out.
Keep turning you trees to obtain an even growth while continuing to spread for red spider mite and aphids etc. Inspect any leaves that may be stuck together as this could mean young caterpillars and damage can be done.
It’s also time to a watchful eye on any wiring as your trees will now building wood that is full of growth and could cut into the branches leading to scaring. Scars. Reduction in growing activity will mean pinching out of leaves will reduce to none depending on what variety of trees you have.
JULY : If you want the best autumn colours for trees like maples then reduce the nitrogen in your feeding. This is the time when water butts are often empty, so fill with tap water, also If your tree is small enough, then place in a container of water to just over the soil level and leave till all air bubbles have completely gone, your tree will thank you for this on a weekly basis. If you have to use a hose keep the pressure low otherwise you could shot blast the soil out the pot, or help solidify the soil and your trees will not thank you for this especially if the leaves are very delicate.
Only leaf prune badly scorched leaves, if they are brown then they are not working anymore. Constant watering will encourage moss, whilst this will enhance the presentation of the bonsai, do not allow to completely cover the pot. One weed that is prolific and unsightly is Liverwort so remove as quickly as possible. Caterpillars can become a nuisance and strip your trees, so beware and have the ready to hand pest control.You will possibly be spending a lot less time in the garden now the trees are in full leave and approaching their best, it’s advisable to take a seat with a cuppa and study them from all angles, make notes on how to plan their future shaping. It might be worth photographing your trees to aid next year’s potential shaping and you can also compare with last years or if none taken, the following years’ photos to see what a difference you have made can also help if you make an error and what you need to do to correct.