
Drosera spatulata
plantlet growing out of the center of a leaf
cutting. Usually you get one plant per leaf.

Drosera prolifera is an easy species
for leaf cuttings. The old leaves are red but still with dewy
tentacles 4 months after being cut off the plant.

Drosera filiformis leaf cuttings with plantlets
floating in pure water.

Drosera binata leaf cuttings in a tube of water ready to be planted out.
Some species of
Drosera are so easy to propagate by leaf
cuttings you can't help accidentally doing them. Occasionally you
can find a pot with a broken leaf sprouting dozens of tiny plants.
Occasionally. Not all species are what could be called easy and
a lot of things can go wrong. But for most
Drosera species,
leaf cuttings are an easy way to propagate plants.
Why do leaf cuttings instead of propagating plants from seed?
Leaf cuttings will produce exact clones of the parent plant. There
is a lot of genetic variation that gets expressed in seedlings.
You generally need to start many more plants than you want from
seed to assure you get a few that are vigorous in your growing
conditions. Leaf cuttings
may be your only option if you want an exact copy of the prize
plant that is already performing well for you or you want to propagate
a sterile hybrid or a plant that otherwise won't produce seed.
As a bonus, leaf cuttings tend to produce mature plants quicker
than from seed.
Not all Drosera species propagate readily from leaf cuttings. Drosera regia leaf cuttings are particularly difficult.
For this species and many others with thick ropey roots, root
cuttings can work well. It is also impractical to make leaf cuttings
of pigmy and tuberous Drosera. The pigmies are usually propagated
from the gemmae they produce seasonally. The tuberous species are
best done by seed or sterile culture.
The first requirement for leaf cuttings is having leaves in good
condition. The best time for leaf cuttings is when the plants
are growing vigorously. You want leaves that are fully open with
lots of dew—probably the best 3 or 4 leaves on each plant.
The Drosera petiolaris group species sprout new plants from the base of the leaf where it attaches to the stem.
You need to pull off the leaf taking the stipule with
it. When you do this you are taking a chance of damaging your plant. But of these species this is the only way to do it and even making perfect pullings is no guarantee of getting new plants.
Most Drosera species sprout new plants from the center or edge of the part of the leaf with the tentacles. It
is painful to do this to the best leaves on your best plants
but hold the leaf in your fingers and use a razor blade or
scalpel to remove the leaf somewhere along the petiole (non dewy part). For species with long leaves such as Drosera filiformis you can cut the leaves into more convenient segments. It also is best not to cut
yourself. Don't like slime with
digestive enzymes on your fingers? Get used to it or wear exam
gloves.
The second requirement for leaf cuttings is
an appropriate medium for the leaves to live until they produce plantlets. Fortunately
there are lots of options here.
The cleanest medium for leaf cuttings is pure water. Float
the leaves, tentacle side up in a cm or so of pure water in a small
jar sealed with plastic wrap. You can also put the leaves into a sealed test tube. This is my preferred method. If the leaves are too long to fit,
cut them into whatever length does fit. Make sure you use pure
water. That is distilled or reverse osmosis water. If the water
gets cloudy, change it. The advantage of water over other methods
is the leaves will survive longer in the relatively sterile water.
This is especially important for ones that are slow starters. When
the plantlets have small roots, plant them in their preferred medium
such as peat/sand.
Other mediums to use for the leaf cuttings are live sphagnum,
dried long fibered sphagnum, peat, peat/sand, or sand. In other
words just about anything that you can grow the adult plants in.
The main criterion is that the leaf cuttings need to kept from
drying out and should be partly covered by the medium to keep them
in contact with it. You can put pots with the leaf cuttings in
plastic bags or sealed terrariums, whatever will keep the humidity
at 100%. The advantage of using mediums with peat are the peat
can somewhat provide nutrients to the leaf and earlier to the plantlets.
Live sphagnum is thought to protect the leaf cuttings from mold
and provides a somewhat acidic medium. And you can leave the plantlets
in the pots for some time as they are already in a preferred growth
medium. The disadvantage of these media is they contain molds,
cyanobacteria, and other organisms that may interfere with the
health of the leaf cuttings. Also the leaf cuttings may move and
dislodge themselves so you have to watch things more closely.
Make sure you put labels on the jars or tags in the pots with
species name and other information along with the date. The date
on the tag is very important. It is going to seem like an
eternity until something
happens in the pots and you can confirm
that by reading the date on the tag.
The rest of the requirements for leaf cuttings are environmental:
light, temperature, and time. The leaf cuttings
need lots of light but you don't want to roast them. It is usually
safe to put them under fluorescent lights but no closer than 8
inches or 20 cm. In a greenhouse it may be best to put them under
the bench or in a shaded location. However there are species such
as the tropical D. petiolaris group species that want rather warm
temperatures.
Now comes the real hard part: waiting and waiting and waiting. Don't
overdo opening the bags. And don't stick your face into them. Remember
we are trying to avoid fungus. Nothing much is going to happen
for the first month or so. D. filiformis
and D. binata may explode out fairly quickly the second month
but others like D. slackii could hang on for 5 months and then
condescend to do something for you. Maybe. Not all leaves will make
it. You may want to remove ones that totally turn brown or get fungus.
But do not give up and definitely don't begin mourning if there is
any green or red left on the leaves.
The thing that amazes me most is where the young plantlets sprout.
It totally blew my mind to see the D. spatulata plantlets
sprouting from the center of the leaf. I was told that is
what would happen but I still was not prepared for it. Right out
of the center of the leaf!!! Other species like D. prolifera do
sprout near the leaf edges where I expected but they will do
it from leaves that look like toast! And then there is D.
binata. Stand back! The plantlets
can be spaced one or two mm apart on the leaves. But most Drosera take
their time, produce a few plantlets, and grow slowly.
-- John Brittnacher