How to get three flushes in a Hawthorn growing season (mid development)
Source: Tony Tickle 202606
One thing I learned very quickly is to never fertilize any deciduous tree until the leaves have flushed out in spring. The reason for that is very simple: as we want internodes to be as short as possible and have a tight ramification on the tree, fertilizing in spring - especially with high nitrogen fertilizers- would push the tree to produce longer internodes. Having too much space between each leaf is is exactly that which we want to avoid. The second problem is that high nitrogen fertilizers stimulate the bonsai tree to produce much larger leaves. That too is not on our want-list.
Wiring and styling flowering apcricot trees is typically done in early spring when the leaves have flushed out and hardened off. It is the only time of the year that the branches are very flexible and will not break off. Don't try to wire at other times of the year, your branches are guaranteed to snap when you do. Use a slightly tighter pitch then 45° when wiring because of that brittleness of apricot branches. Better use a thinner wire and double up, rather than using a thick wire.
by Eisei-en (Bjorn Bjorholm) Defoliating Flowering Apricot Bonsai