Can I stimulate another round of new growth
 

Please forgive me if this is going to be a bit long-winded but I want to get all the detail down at once.

Also, please note I'm in the Southern Hemisphere so seasons reversed.

In autumn last year I bought about 35 young cattleya-alliance plants in 50mm (2inch) pots. Most are hybrids, mostly being largely from unifoliate parents, with a few predominantly bifoliate cluster types. There are also about a dozen which I bought as 'cold tolerant laelias' (anceps, purpurata, crispa etc and hybrids).

I kept all these plants inside over winter and by late winter they were showing signs of new growth so I repotted them in the next size mesh pots.

Then they went through about a month of neglect while we moved house, but by early summer I had them settled outside in a shadehouse.

I grow them in a mix of pine bark and charcoal, water 2 of three days and fertilize weakly, weekly with an 'orchid fertilizer'. Light in winter was a bit inadequate but I keep the shadehouse bright.

Anyway, they must like my regime because their general condition is excellent - there's hardly a leaf blemish or insect bite across the lot of them.

Now, just short of mid-summer, the new growths have grown strongly and now are about 4 to 8 inches long, which is about all I would expect for the age of the plants, and the bases are swelling into psuedobulbs.

So my questions are

1. is that it for the year? I understand that orchids have defined periods of growth and rest, but does that mean they intend to take the rest of summer off, or is there something I can do to stimulate them to produce another round of new growth ?

2. if there is, is it a smart thing to do? There should be about another three months of summer-type weather. Is that enough, or might it lead to sickly growths? Or will putting the plants through another growth cycle perhaps prejudice their growing season next spring ?

One thing we dont have to worry about is the new growth being hit by frost. We are new in the area so not exactly sure of what to expect in winter but I think winter minimums should be about 48farenheit outdoors and 57f indoors in the unheated parts of our house. I'll probably take indoors the ones I think are sensitive and leave the hardier looking ones in the shadehouse.

cheers and thanks for reading
Arron

I think you should just keep doing what you are doing. Orchids seem to do things when they want to. They will probably soon start another growth anyway. There really isn't anything you can do. I have Cattleya's in all stages of growth now and I'm in winter.

Remember, it's the new roots, not new growth that you need to look for if you need to repot. Most species have a definite rooting time, usually once a year (though there are exceptions), hybrids may root more often, influenced by different parents. But in general, it's all about roots.

in cattleya types.....the new 'leaf' and its base 'psuedobulb', grow from the rhysome, which likes to crawl around on the surface of the media....new growths come from the mature base of the psuedobulb where it joins the rhysome. the leaf and psuedobulb must be mature to grow new leaves from that base. it will usually have 2 growth 'eyes' showing, and normally only one of them grows a new leaf. the remaining 'eye' is held in reserve in case of damage to the growing one....

there are a lot of 'usuallys' involved in orchids...they will fool you every time they can, lol....I think there is a mischievous imp in each one!

here in texas i am keeping my little gh warm, minimum of 65 degrees simply because natural gas is cheap....but in the past, i have kept a min of 55 degrees for my cattleyas....

as far as encouraging more growths per year, if you find a way, let me know! as long as the roots look good and there is some growth, i am happy!

Orchids pretty much do what they want to do, when they want to do it. To facilitate them, you have to observe what they're doing and go with the flow to facilitate what they want to do naturally. Orchids teach patience.

In warm areas such as where you are, hybrid Catts often grow continuously. Especially seedlings do this. I would expect to see more growth very soon.

I had a look today and was surprised to see that about one quarter of the plants actually do have a second round of new growth occurring. I hadn’t noticed.

The newest growths are still small, about one half inch long or less at present. And they do look different to the previous growths - like the leaf tips are already separating and turning back from the stem.

Mostly these newest growths are emerging from the opposite side of the plant to the previous growths. It will be interesting to see how they progress - whether they are able to mature into sizeable pseudobulbs.

Obviously I still have a lot to learn about how these things grow.

Thanks for the responses
Arron

There is a meristem, thus a potential new growth, at the inner base of each bract and leaf on almost all plants, including orchids. These are often called "eyes" in orchids, and you can often see dormant growth buds on the rhizomes.

Most Cattleyas alternate sides over time when breaking eyes from previous growths. This keeps the plant growing in a straight line. I have seen a few that consistently break only to the right or left; these plants tend to grow in circles.

When the plants get older and stronger, they often break more than one lead at a time. This is especially true with hybrids, which are often more vigorous than species.

I'm still curious about this.

I took a photo to show the kind of new growths that are emerging on some plants.

In these two plants I've marked the previous new growths (now well advanced) and put arrows pointing to the latest growths. As you can see there is one on the plant on the left, and two on the right hand one.

I don't remember previous new growths looking like this. Not with the short, turned-back, spreading-out leaves - I think the previous ones stayed smooth and compact until they had gained some length, but these ones seem to be differentiating into fully formed leaves at a very small size.

I'm not worried about the health of the plants, I'm just curious if this is common and whether the new growths are on their way to being good, sizeable pseudobulbs - or whether they will stay some sort of small stunted thing?

cheers
Arron

The new growths are just smaller yet. And even better, looks like two new ones growing at the same time - meaning that you may very well get flowers from both when they get to that point. That is a really vigorous plant.