Propping Cuttings

Propagating by cuttings is a quick and effective way of growing a plant. Taking a cutting is like making a clone of the mother plant, this means we will get a more predictable and consistent plant than when growing from seed. Many plants can be grown from cuttings although some are best at certain times of the year, softwood cuttings are taken in spring and hardwood cuttings in autumn and winter.

There are many ways to grow cuttings. Some plants need more attention and care, others can just be pushed into the ground outside and ignored. The key to growing cuttings is to keep them moist and not let them dry out. Most cuttings appreciate a humid environment and warm growing medium. Both Plant Barn and the NMIT nursery have a hot bed and misting system for cutting trays and seed raising.

Above is a cutting tray at NMIT with a mix of sand, vermiculite, potting mix, and pumice. At the Plant Barn we use straight pumice in our cutting trays. This provides excellent drainage, and we can reuse the pumice a number of times. We use ibadex, a powered rooting hormone, and plant the cuttings in rows about 1cm apart. I have also heard of nurseries using sand as their cutting mix, anything with good drainage is appropriate.

At home I find propagating plants in water is the easiest, particularly for houseplants. Recently I was given the responsibility of growing some climbing plants. I cut the vines into individual nodes/leaves and placed some in water and some in moist sphagnum moss.

This photo shows two Monstera adansonii cuttings, the left one was sitting in water, the right one was in sphagnum moss. The plant in sphagnum moss has grown a much larger root and has begun to put out a new leaf also. This may be because I was able to use a rooting hormone clonex with the moss, I didn’t bother in the water as I thought it would not be effective. Sphagnum moss provides excellent humidity and holds moisture well so the roots never dry out. It is proving to be an excellent propagating media for tropical house plants.

What cutting media have you tried? What do you think is the most successful?

Moving away from sprays

Lately my course has been focusing on pests and diseases in nurseries. Appropriate timing in Spring, the warm and damp weather is the perfect breeding ground for many garden pests. I have been dealing with mealy bugs, aphids, leaf miners (pictured below) and spittle bugs in the garden at home. It seems the more I learn, the more pests I find!

I believe it is important to find a more natural solution to pest control before resorting to nasty chemicals. This year I have tried to utilise some companion planting in my vegetable garden. I have planted calendula throughout the garden to attract beneficial insects and marigolds (pictured below) to keep away pests like whitefly and aphids, they are repelled by the scent. I am finding this is working well. I also have a homemade spray that I use on aphids which is effective. I fill a spray bottle with water then add two teaspoons of each- baking soda, vinegar, dishwashing liquid. I only use this if I cannot pinch off all the aphids, because it is damaging to beneficial insects also.

In a nursery situation it is harder to use natural remedies, but it is possible. Bioforce sell a number of beneficial insects for pest control. Biological controls create a healthy eco system and are much safer for the plants. Pesticides can be damaging to plants and unhealthy for the consumer, particularly if it is a consumable plant.

At NMIT we have experimented with two different biological controls. First we released some Hyper-Mite, these feed on fungus gnats which are a huge problem in our nursery. Next we released parasitic wasps, Aphidius colemani which target aphids. The mites were sent in a compost mix that we sprinkled on top of the pots, they are under 1mm so very hard to see! The wasps are bigger at 3-5mm and were visible in the small vile as pictured above. We are yet to see the results of these pest controls. However it seems a lot of nurseries are beginning to adopt a more natural pest control as we realise how bad chemical sprays can be.

Carnivorous Curiousities

Spring is well and truly here with its longer days, unpredictable weather, and lots of new plant growth! I love watching my carnivorous plants come out of dormancy and start to flourish again. I have a small collection of pitcher plants, sundews, and Venus fly traps. They all live outside except for my Nepenthes (a hanging pitcher plant), which prefers a more humid/tropical environment. They are happy outside because they like to have a period of dormancy over the winter, some species even survive being covered in snow! I love their unusual appearances and find them very easy to look after as their main need is plenty of water, I have them sitting in deep trays which I just keep topped up with rain water. They are swamp plants so they don't like nutrient rich soil, I normally use straight sphagnum moss for small plants and a mix of peat, sand, and perlite for larger pots. Carnivorous plants feed on living insects, another good reason to keep them outside- plenty of food!

 

Three different types of pitcher plants. From left, Sarracenia minor, Nepenthes (indoor), Sarracenia rubra (?) in flower. The plant produces a digestive liquid in the bottom of the pitchers, the sides are smooth so insects fall into the liquid and then cannot escape.

There are around 200 different species of Drosera (sundews) and they have been found all over the world! Sundews secrete a sticky substance along their leaves which bugs get stuck to, then the plant slowly digests them. Some sundews curl up around their prey to ensure it is well stuck. The photo on the left shows a forked-leaf sundew (Drosera binata- native to Australia and NZ) with a moth stuck to it. You can see the little hairs coming off the leaves, with sticky droplets on the end of each one, these hairs also curl towards the prey when they feel movement. Photo on the right shows a different sundew in the front, and a Venus fly trap in the back, after being potted up last Spring.

                               

This is a native spoon-leaved sundew (Drosera spatulata?) I found in a swampy area in Arthur's Pass, it accidently fell into my bag (don't tell DOC 😏). I have had it for nearly 5 years and it has self seeded. It is my smallest carnivorous plant but my absolute favourite!

The most popular carnivorous plant of all is the Venus fly trap (Dionaea muscipula) and it's not hard to see why. This plant is amazing to watch. The leaves are deadly traps for insects. They have tiny hairs inside the leaves that trigger when touched, causing the trap to spring shut and imprison the insect. These traps will change in colour, with more sun over Summer they go a brighter red in the center of the traps. Some of my sundews and pitcher plants also change from green to red with higher light levels.

If you're looking for more information check out www.carnivorousplants.org- The International Carnivorous Plant Society. Or feel free to ask me a question and I'll do my best to give you an answer!