Root life cycle.

[bil]

OK, it's nice to be able to ask questions here without having people saying 'That's a dumb question' etc etc so thanks to all who help out.

It's sometimes very difficult to ask a question clearly unless you already know the answer. That might sound silly, but thrust me, it isn't.

Do orchid roots have a lifecycle? By that, I mean a 'normal plant like a rose pushes out roots, and while they may die off or die back, in general such roots are there for the life of the plant. Plus, of course, cut off all the roots, and the rose is what we gardeners call 'dead'. From the rescue hard cane dens I salvaged on their way to the Great Compost Heap in the Sky, I can see that an orchid with no roots is not a dead plant but will happily throw a whole new set of roots while living off their 'fat'.

Are there orchids whose roots die off each year? Or do a % of an orchid's roots die off each year. Do roots just last a fixed number of years and die off, or, barring accidents and with good treatment, will an orchid retain all its roots as long as it lives?

[Orchid Whisperer]

Roots on an orchid are a bit different from those on a rose (which are woody). Certainly on sympodial orchids, a root lasts no longer than the rhizome it is attached to, and often less. Monopodials like Phalaenopsis also have a lower stem below the leaves that dies back as the plant grows taller, and roots attached to that stem die back.

I suspect that roots, like leaves, die whenever they can no longer help the plant, and are replaced by new roots. I don't think you can have an orchid root that has a very long life like a rose root; a few years is the most you can expect before the root dies and is replaced.

[bil]

Originally Posted by Orchid Whisperer

Roots on an orchid are a bit different from those on a rose (which are woody). Certainly on sympodial orchids, a root lasts no longer than the rhizome it is attached to, and often less. Monopodials like Phalaenopsis also have a lower stem below the leaves that dies back as the plant grows taller, and roots attached to that stem die back.

I suspect that roots, like leaves, die whenever they can no longer help the plant, and are replaced by new roots. I don't think you can have an orchid root that has a very long life like a rose root; a few years is the most you can expect before the root dies and is replaced.

Yeah, that all makes sense. What puzzles me is why so many of the orchids that I buy have roots that frankly look abused. You'd think that pro growers would produce plants with fabulous roots, but several of the cats I have bought the roots were awful. short, shrivelled and third rate. To the point that I was wondering whether the roots on a lot of orchids die off completely each year and then they grow a new set.

[bil]

Here are two pics to illustrate. One is the soft cane Den that had the dry, fine wood wool roots, and the other a Cattleya that had no roots worth speaking of.

They are both now putting out these plump, succulent new roots.

[tucker85]

I don't know the answer to your question, but I do know that orchid roots last more than one season. I grow in South Florida in open wood baskets. When I use a root stimulator, like seaweed extract, I often see new root growth branching off of roots that are 2-3 years old.

[bil]

Originally Posted by tucker85

I don't know the answer to your question, but I do know that orchid roots last more than one season. I grow in South Florida in open wood baskets. When I use a root stimulator, like seaweed extract, I often see new root growth branching off of roots that are 2-3 years old.

So, do those roots shorten, shrivel and dry out as they age?

[UnstuckinTime]

Plants go about making their organs differently than animals do, for sure. In general, roots are the "nutrient and water acquiring" organs, and leaves are the photosynthetic organs (though there are many plants that break this rule!!)

While it's true that a plant like a rose will suffer if you chop off all it's roots, any gardener will tell you that you can take a stem of a rose, put it in water, and it will grow new roots. This is exactly the same as pulling off all the leaves of the rose bush, and the plant grows them back (like pruning!). Our orchids do the same thing, but the way they grow makes it look different.

For cane/pseudobulb producing species, you can think of each cane/pseudobulb as an individual plant. It grows it's own roots and leaves, but when it reaches the end of it's time, it makes a new plant from it's base and will itself senesce. In this case, the roots will only last as long as it's connected plant will.

For your phalaenopsis-type plants, they grow along a single axis (except by forming keikis), constantly making the stem longer and longer, with the older stem dying (for physiological reasons that I don't need to bore you with). As new photosynthetic organs are produced, and the stem gets longer, new roots have to be made because the older ones, attached to the older stem, die as the stem dies. If a root is damaged by other means, but is still attached to a living stem, it may try to branch.

So, yeah, you could say roots have a life cycle, though that probably isn't the term I'd use. They just have... expiration dates!

[Hiester]

What I've noticed over the years is the velamen can often start to look really dreadful, but inside there is still a viable, wiry root filament which is still capable of absorbing water and nutrients. I don't think orchid growers have much control over how well the velamen ages over time, appearance wise.

---------- Post added at 11:41 AM ---------- Previous post was at 11:29 AM ----------

A little more detail to the points that UnstuckinTime has made... monocots and dicots produce new growth in different ways, generally. Most all dicots, if not all, are capable of both primary and secondary growth, whereas monocots (orchids are monocots), in general, only produce primary growth. In essence what this means is once the growth has matured in orchids (and most other monocots) their stems and roots no longer continue to expand in circumference (that would be secondary growth, which is the realm of dicots). This fundamental difference in the two groups accounts for some of the differences in the appearance of plants. There are some exceptions to these generalities. Gymnosperms act in a similar manner to the dicots.

EDIT: Corrected spelling

[bil]

Originally Posted by Hiester

What I've noticed over the years is the velamen can often start to look really dreadful, but inside there is still a viable, wiry root filament which is still capable of absorbing water and nutrients. I don't think orchid growers have much control over how well the velamen ages over time, appearance wise.

---------- Post added at 11:41 AM ---------- Previous post was at 11:29 AM ----------

A little more detail to the points that UnstuckinTime has made... monocots and dicots produce new growth in different ways, generally. Most all dicots, if not all, are capable of both primary and secondary growth, whereas monocots (orchids are monocots), in general, only produce primary growth. In essence what this means is once the growth has matured in orchids (and most other monocots) their stems and roots no longer continue to expand in circumference (that would be secondary growth, which is the realm of dicots). This fundamental difference in the two groups accounts for some of the differences in the appearance of plants. There are some exceptions to these generalities. Gymosperms act in a similar manner to the dicots.

I'm just struck by the difference between purchased plants with roots that are like a shrivelled bird's foot, and some pics on here with long, plump luxuriant roots.

[tarev]

I think it is the time of the year when you buy them. They grow in seasons, so if you chanced upon getting them in their active growing season, then you will see the happy new roots forming. Though it also depends on the type of care and culture given to it by the grower, so the older roots will be okay too, but as mentioned already, those old roots will eventually go out and be replaced by newer roots if it is getting its growing culture right.