Question
I hope it's OK to ask several questions in one post!  Thanks in advance for your expertise.

1. Christmas cactus. Mine is pretty healthy, but I want to know: I've heard that the branches should be no more than two leaves long before they branch again or flower. Is this true? Also, should I wait until it is drooping to water (from below only of course)? Will a fertiliser for succulents work all right? Also, my plant is growing new leaves right now. What can I do to ensure that it blooms when it should, around December?

2. Avocado plant. I got this crazy creature to FINALLY send up a shoot, but it persists in only growing one branch, despite my pinching it off. Then that one branch will sprout leaves, which mature, with another sprout coming on among them. The the leaves abruptly dry and fall off, and the new sprout leaves mature...same thing all over again. What can I do to get it to branch and sustain leaves?

3. I just bought two beautiful shamrock plants which I am about to repot and leave outside for the duration until fall (I am in zone 5a). Do they need pest protection? When I bring them in for the cooler weather, how should I fertilise them?

My houseplants are all in a south-facing window that gets a lot of sun in the winter, but is shaded in the warm weather because we are in the woods. The window is new and tight against cold, and is not near a vent.

Thanks again for your help. :>)

Answer
Hi Eleanor,

It is better if you post separate questions individually. That makes it easier for other who come after you to search for an answer to similar questions.

CHRISTMAS CACTI branch spontaneously or you can pinch out new growth and that will often cause them to branch at a location of your choice. There are no rules about how many segments should go between branches. It is purely a matter of personal taste.

Following winter bloom, it is best to allow the soil to stay dry to the point of nearly wilting while the plant enters a semi-resting stage. For the rest of the year, it is best to water when the top quarter of the soil fees dry and that is usually before it starts to wilt.

There is no particular reason to water a Christmas Cactus (or most other potted plants) from the bottom. Bottom watering is more difficult because gauging how long to leave a plant sitting in water or how much water is difficult for most folks. If you are successful at doing it, good for you. Otherwise, water from the top and discard any excess water that flows into the saucer.

There is no special fertilizer for succulents. That is a marketing gimmick designed to get you to buy multiple kinds of fertilizer for different kinds of plants. Most all of your potted indoor plants do fine with a 3-1-2 ratio fertilizer that includes trace elements. Use it at half strength monthly and only when your plant is healthy and growing vigorously. Fertilizer is not medicine and its value is highly over-rated. Pay attention to pot size, light and water, as they are what make the difference between healthy and unhealthy plants.

The key to getting holiday cacti to flower is to provide a cool period with shorts days in the fall. If you can summer your Christmas Cactus outside in shade that is best. Then, when cool temps arrive in the fall, leave it outside until night temps drop to about 35 degrees but no lower. Your plant will use less water in the cooler weather. The cool temps and shorter hours of daylight are the keys for setting buds. Once the buds are well-established or temps drop close to freezing, bring it inside to a sunny windowsill. Resume normal watering and enjoy the buds as they open.



AVOCADO plants do not branch readily. Their growth habit is mostly straight up. As indoor plants in reduced light, the stems are usually tall with large spaces between the leaves. Pinching back new growth will occasionally, but not reliably, cause a secondary branch to emerge.

If leaves are turning brown and dying, it could be lack of light or improper watering. Avocado is a high light plant that should be in a sunny window indoors. It grows best when kept moderately pot bound and watered when the top inch of soil is dry or if leaves start to sag a bit. Fertilize it sparingly at half strength monthly when it is putting out healthy new growth. Eventually you will have to prune so it doesn't outgrow its space. Personally, I think this is more of a novelty plant that we like to grow from a pit. But it doesn't make a very attractive potted plant.


SHAMROCK (Oxalis regnelli) are much less vulnerable to root rot and more likely to flower if they are left in their nursery pots. You can hide the unattractive nursery pot by placing it inside a more attractive planter, but leave the roots undisturbed for best results.

When kept indoors, spider mites are the most common pest problem for Shamrock. Outside, they are susceptible to whatever insects like them and are native to your area. For that reason you may want to keep yours indoors.

Shamrocks have a winter dormant period that must be respected. Starting in September, stop fertilizing and gradually reduce the frequency of watering over the next month. The leaves will gradually die and you should then cut them off. By mid October you should stop watering altogether and move your Shamrock to a cool, dark place where you can ignore it until February.

In February, you will see some signs of life. That is the signal that you can resume normal watering and fertilizing and move it to a sunny windowsill until the following September. I

Oxalis has small bulbets or corms just below the surface of the soil. These can be pulled away from the plant and put into their own pots. However, this is best done at the end of the plant抯 dormant period in February.


It sounds like your south window is  good location for most indoor plants.


I have written an article on Christmas Cactus care and also articles on repotting and fertilizing that I will email for free to you (or anyone else) who emails a request to me at [email protected]. I have also written an indoor plant care book in a PDF format that I can sell you if you contact me at my email address.

Please let me know if any of this is unclear or if you have any additional questions.

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Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

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