The first step is to identify which plants you hope to cross. Do you want to make a new hybrid or just set seed on a particular species?
Some people would rather never see a hybrid, but interesting plants can result. For example, it’s difficult for me to grow both A. warocqueanum and A. papillilaminum in the summer here in South Florida. They just don’t like the heat. However I have a hybrid of the two, originally done by John Banta that grows like gangbusters!
Setting seed among the same species is a great way to increase the diversity. Cuttings are just going to be copies of the plant you started with, but your seedlings will vary a bit. Some are stronger than others, some grow larger, etc.
On an inflorescence the female flowers mature first, followed by the male a little later including pollen production. The inflorescence is ready to accept pollen when tiny droplets of moisture, stigmatic fluid, can be seen on the spadix. This is referred to as anthesis. Often there is even a scent associated with this event. These are pheromones that would normally attract pollinators. In this case, that would be you. First use a paintbrush, your fingers, or collect fresh pollen into a paper towel. Then brush or rub the pollen onto the receptive female flowers. Do this for a couple days in a row if possible. (What the heck, right?). Basically, the biology of it is easy... You need a receptive female spadix AND fresh pollen from another plant. The female flowers are usually only ready for a day or so.
One of the main roadblocks to pollination is not being able to have two inflorescences ready at the same time. It’s a good idea to freeze pollen if there is a specific plant you want to put the pollen on. You can achieve this by using a paintbrush to brush the fresh pollen onto aluminum foil, fold it over, label it and then put the whole thing in a freezer zip lock bag. Make sure you label it with the name of the plant it came from. It’s also a good idea to label the inflorescence you put the pollen on with the pollination information on it. Believe me, you will NOT remember what pollen you slapped on which plant 6 months down the road, especially if you are doing many crosses.
Sometimes very different looking Anthuriums from within the genus can be crossed, but usually plants from different ‘sections’ will not cross… much to my annoyance. I mean, we all need a velvety leaved A. veitchii, right? Obviously there are exceptions.
For some reason I find many of my most mature plants will self pollinate nearly every time they flower. It is impossible to tell if pollen I meticulously applied “took” and will result in a way cool new hybrid, or just selfed again until the resulting seeds are planted and have grown out. If they are eaten by snails or succumb to fungus, you can be assured that your hybrid probably had been a success!
It can take many months for the berries to form before you see if your pollination efforts have been a success. The mature berries can be many different colors depending on the species. Red, purple, orange, red, white, or even green. Usually the color is the same among plants belonging to the same section.
If propagation by seed is too time consuming, (it certainly is for me) vegetative propagation may be preferred. This is basically just taking cuttings. I never do this during the winter. Usually not after October here in South Florida. Simply because as the days get shorter, you are less likely to be successful. You may lose both the cutting and the mother plant by over zealous cutting at the wrong time of year.
I normally start cutting on March 1. Get out of the way!! I’ve got knives, clippers and machetes depending on the size of the plant. If it’s a more delicate or valuable plant, I may even wait a bit longer. By June, I can cut anything and throw it in the bushes and it will still root quicker than a March cutting.
If you have mist on a timer you can be a little more aggressive with cuttings. They will root much more quickly and easily. Normally the top portion is cut off with some roots and planted in a very well draining mix or sphagnum moss. Sometimes there are offsets form the mother plant that you can separate. I also do stem section cuttings. I will cut a section of stem into about 2” pieces, making sure there are at least two nodes and set each in its own pot sideways. This has worked out great for me, but this is best left for growing season. Another note… I have found that putting the new cuttings in a bit brighter light than you would normally grow Anthuriums in seems to aid in the success of rooting.
Anthuriums grow best in tropical areas or greenhouses. They really prefer to be warm for best growth. Temperatures in the 70-90 degree range are optimal. Anthuriums will not stand for freezing temps.
It is very important that Anthuriums are planted in a well draining soil mix. As with many aroids, they like lots of water, but they certainly don’t want to sit wet. A good rule of thumb is that if the soil is still wet from the last watering, it doesn’t need more water. That is the quickest way to rot them. Don’t be afraid to stick your finger in the soil a couple inches. It’s often dry on the surface but sopping wet in the middle. I love the large chunks of perlite and tree fern to add to a peat based mix for optimal drainage.
Another unusual thing about many climbing aroids is the absolutely amazing difference between an immature plant and a mature plant that is left to climb. Totems (or trees if you live in a warm area) are best. When I first started collecting aroids it occurred to me that I was repeatedly buying the same philodendron in different stages of maturity!
I’ve also found that Anthuriums, especially some of the large leaved varieties, love to have a nice totem and added sphagnum. Not only do they get larger leaves, but they can sometimes snap their own necks from the weight of their own leaves if they don’t have some support. If they were still growing in their native habitat, they would be climbing a tree with all kinds of leaves and other plants all around them for support.
I usually use baskets with soil and moss packed around them for the hanging anthuriums. This gives them the room for the leaves to grow down while offering proper drainage. The roots will attach to the wood and hang out of the basket. They do well this way, but I find it a pain to repot them. I just usually repot the whole basket into the new one, so as not to disturb the roots. These species usually grow in trees or on the sides of cliffs. Being epiphytic, anthuriums really need proper air circulation as well.
I have a few species planted right in tree fern pots. These do great as long as they don’t dry out. Alternatively you can even set the pot in a shallow dish of water. A half inch is fine. This is called wicking, and as long as it is only a little water, they do great this way.