There are many species suitable for bonsai.
I am going to concentrate on varieties of Ilex vomitoria for they are
what we use the most. All growing conditions mentioned here will be
suitable for all Ilex’s.
Ilex vomitoria Yaupon Holly This Holly has dense compact growth
and small scalloped leaves. The female produces small clusters of red
or yellow berries.
Ilex vomitoria ‘Schillings Dwarf’ Tight compact
growth with leaves about two inches. Flowers in spring but generally
doesn’t produce berries.
Ilex vomitoria ‘Nana’ Dwarf Yaupon Holly Almost
identical to the Schillings Dwarf, their leaves are slightly smaller
and it does produce berries. The easiest way to tell the difference
between Nana and Schillings is the new growth on the Nana is green as
where the new growth on the Schillings is red. Berries only appear on
Ilex vomitoria ‘Pendula’ Weeping Yaupon A dwarf
weeping Holly that does berry.
PRUNING... The top can be heavily pruned as
long as you leave a few leaves on each stem. More so on collected
material as to nursery grown material. I will prune the top back and
then wait until it starts flushing out to prune the roots. On large
cuts, spray with Lysol and then seal. If removing a large branch on the
top of the tree, do not use your concave cutter. Leave some stub and
then carve that back so it is somewhat rounded up to repel water. Water
can sometimes enter a large cut and rot out the center of the tree.
TRAINING... Wiring can be done on secondary and tertiary
branches. Branches tend to get very brittle as they age. Clip and grow
works well. Prune back to two leaves for tight growth. They grow quick
so will require periodic pruning through the growing season. Be careful
not to allow the branches to get too full of foliage for that will
block the light from the inside of the branches and decrease air
circulation which will result in your inner leaves dying off.
WATERING... Do not allow to dry out. I water mine well through
the growing season and less through the winter.
LIGHT... Full sun, starting with the morning, for if their leaves
stay too wet through the morning they can suffer a fungal die back of
their inner leaves. They can suffer some heat stress in July and August
so I give them a break from the afternoon sun.
INSECT/DISEASE... Leaf miners can be a problem and if stressed
scale and mites can occur. Sometimes suffer a systemic fungus problem
that can kill a whole branch and sometimes the whole tree. At second
repotting wash all of original soil off, that which came when collected
or from nursery pot.
FERTILIZE... A heavy feeder through the growing season. I use
Osmocote and feed bimonthly through the summer with a water soluble
REPOT... Can be repotted from spring through summer. On first
planting be careful not to take too many roots at once, generally best
to reduce root ball over several plantings, removing 1/4-1/3 at a time.
SEASONAL... Cold hardy here.