Winter rest periods: Do we need 'em?

...and the questions just keep on coming. I'm guessing they might not have definitive answers but I'd still be very interested to hear anyone's opinion or experience of house plant winter care, especially at more Northern latitudes. I've been thinking a lot about this subject as, in terms of light conditions, we're almost in mid-winter here in the UK (down to 8 hours daylight and often of poor quality); however a lot of my plants show absolutely no signs of slowing growth. In fact, I'd swear that some of them are growing more vigorously now than they did in the summer (with double the daylight hours!).

Before I discovered Dave's Garden all my plant knowledge came from the few decent house plant books I could find and all of them mention winter rest periods where growth slows down or stops, where watering is reduced and feeding is stopped or drastically reduced (admittedly they are all published in the UK and aimed at British readers with their very pronounced differences in summer/winter conditions). One source mentions that plants need 12-16 hours of daylight to maintain active growth, so why do a lot of mine continue to flourish? I'm making sure that they are kept just moist (no overwatering), the temperature is not excessive (around 60º - 65º F, as recommended for most plants during winter, in all the books I've read) and feeding has been very much reduced/stopped. So I'm pretty sure I'm not forcing the plants to grow against their wills!

So here are some questions:

• Should I worry about plants not getting rested over the winter months?

• If they continue to grow on the levels of light they are receiving should I just be happy about it and give them water, warmth and fertilizer as normal?

• Will they suffer by continuing to grow through winter, and if so, should I "encourage" them to rest by reducing light levels, temperature, feeding further? (Although I'm assuming that a lot of plants don't have any rest periods in their natural environment as there is not such a marked difference in seasonal conditions?)

•Is it still too early for some plants to "rest".

• Has the importance of the "rest period" been exaggerated?

I apologise if some of my questions are a bit dumb, but I really don't want to lose any plants over winter by not caring for them properly.

I look forward to any/all replies and thanks for reading this far!

Paul.

BTW, here are some pics I just took - Epipremnum continuing to climb; Monstera putting out another big leaf; Ficus elastica branching (I find this strangely exciting, lol); new Schefflera elegantissima leaves; Aglaonema continuing to flower; Chlorophytum having babies!

I believe in the old saying...if it ain't broke, don't fix it.
90% of my houseplants I don't worry about a rest period. I continue to water and fertilize the same all year long.
My Christmas Cactus though, I do cut back on water and put them in a cold window to induce flowers. A few Hoyas get special treatment too.
A couple of things...bougainvillea, Plumeria, etc., I will let go dormant but only because I don't have enough sun to keep them happy and to save on space.

Let your plants tell you what they want.

Your plants are each programmed with a genetic response to increasing/decreasing photo-period and photo-intensity. Some plants can be tricked into growing robustly all year long by manipulation of these influences, and others are stubborn about a period of quiescence or slowed growth no matter how you manipulate light. Basically, I guess I'm saying "Don't worry too much about it. Concentrate on providing the best cultural conditions you can, with what you have to work with, and leave the rest to the plant.

Al

Thanks, these are the kind of answers I was hoping to receive. About cacti, I have mine sitting at a south facing window but in a heated room, over winter. I do have an unheated room but it faces north. What is more important over winter for cacti, bright light or cooler conditions? Unfortunately I don't have an unheated room that gets direct sunlight so it's a bit of a trade-off. Or is it a misconception that cacti prefer to be kept on the cool side over winter?

This message was edited Nov 15, 2009 9:15 PM

My Christmas cacti are in a heated room but on a cold windowsill (200 year old windows). It gets them to bloom.
My regular cacti I keep in a cold room, just because it is the only place the cats can't get them, and cut back the watering. They don't seem to care about the light since they stop growing.

I think I'll move mine into my unheated room then, I've already got some succulents in there already. Makes sense to treat them the same.

Well, your plants look happy and wonderful. Mine are not resting yet either. I am fertilizing very weakly. I think that if the growth starts to stretch too much, that's when I'll worry, or just wait it out until the spring when they all move outside.

As far as I know, it's day length not temperature that triggers Christmas cactus to bloom. Being cool won't hurt it, but I don't think it's necessary. If yours doesn't already have buds, then I'd put it somewhere that it doesn't get a ton of artificial light during times when it's dark outside. If it does already have buds I would leave it alone--moving them and changing their conditions can make them drop their buds.

In their natural habitat tropical plants do not have a Winter rest period. Conditions are very similar year round.

Tropical conditions are generally warm, humid, well ventilated and about 12 hours of lighting per day. You may consider supplemental lighting if they are not getting much light indoors during the Winter.

I was talking about regular, desert cacti before, my fault for not making myself clear. However, I do have a couple of Christmas cacti in my unheated room and they are blooming away on the windowsill.

Thanks, Metro. I've so many plants all around the house that supplemental lighting would be a bit of a problem. However, I have been wondering about turning my spare room into a 'plant room'. It has a large, built-in wardrobe that I use for storage and which I thought could be turned into a large, terrarium with sliding glass doors, artificial lighting, humidifier etc. Probably just a pipe dream but, who knows, if I win the lottery!

I'm assuming that I should keep fertilizing my plants if they continue to grow. If so, how weak should it be? Miracle-Gro suggests 1/4 capful per litre of water, would this be too strong for winter growth?

3jsmom, I wish I could put plants outside but even in the summer the weather is so changeable here they could be drowned, scorched, frostbitten and blown away all on the same day!



This message was edited Nov 15, 2009 10:01 PM

ecrane: You can use either method, temps in the 55F range will start buds, as well as 12 hours uninterrupted darkness for weeks.

Paul, I have nothing to add except to say your plants are beautiful and very healthy looking, you've done a great job with them.
Christine

As tropical plants don't really have a Winter growth period, maintaining a regular fertilizer program should be fine. If your Winter temperatures are significantly cooler than the rest of the year, it might be good to water a bit less.

Actually, the winter temperatures aren't significantly cooler (indoors I mean), as the central heating is on almost constantly. Still, I'll err on the side of caution and be careful not to overwater.

Thanks, Christine. I'm sure they look good in spite of me, not because of me! Look at the state of that Monstera leaf in the background, that's not good!

Even though tropicals have no period of rest where they naturally occur, almost all slow down considerably (quiescence) in the more southerly and northerly latitudes, unless you are able to maintain a favorable light level and intensity, and favorable temperatures.

How often and at what strength you can or should fertilize depends on the relationship between how well your soil drains and your watering habits, so there is no singular answer we can appropriately give w/o knowing something of that relationship.

I'll explain. If you're growing in a slow soil that doesn't drain well (most commercially bagged soils) during winter, you'll almost have to reduce the amount of water you give the plant to just sips to prevent the specter of root rot from raising its ugly head. When you water in sips, it doesn't take long for the accumulation of salts from tap water and fertilizer solutions from a regular fertilizer program to create serious problems for plants because all the salt from both sources remains in and accumulates in the soil, so fertilizing at your regular rate could be entirely inappropriate.

OTOH, if you're growing in a fast soil that allows you to water properly, so that you apply enough water each time you water to flush accumulating salts from the soil, there is no harm in fertilizing regularly, or even at low rates every time you water, which is what I do.

Al

Thanks, Al. I was a bit lax this year with repotting so most of my plants are still in their original pots/soil. I have a few plants that are obviously in quite poor soil but most of them I've bought from reputable nurseries, where I'm assuming the soil is of good quality. Water certainly seems to go through the pots fairly quickly with most of them when I water.

Tropicals such as Epipremnum & Monstera can handle being on the dry side a bit. They are quite tolerant of a wide range of conditions.

Here is Epipremnum pinnatum 'Aureum' growing close to the coast in Hakalau on Hawai'i Island. It suffers through wind and salt spray, wet and dry conditions.

You'd be amazed at what a similar-sized Epipremnum would cost to buy in the UK. I'm assuming they just grow like weeds in Hawai'i? I actually have a smaller Epipremnum in my bathroom and have noticed that the variegation seems to be stronger on the new growth than on this summer's leaves. Shouldn't variegation be stronger in better light conditions?

This message was edited Nov 15, 2009 11:11 PM

Yes, they are serious weeds here!

Diseases & pests do not harm them. They outgrow everything. Herbicides will knock the leaves off, but the stem always survives and regrows.

OMG Metro,

I just LOVE it when you post pictures... Like the one by the water.. BEAUTIFUL!

Me, too. It is fantastic to see what the plants look like naturally. It is quite different than what we see here in hanging baskets. I have had that plant for years and it still has 3" heart shaped leaves draping down. I am thinking about building totems and climbing all my philo kin.

Pauliewalnuts: Please tell how your totem is made. I did one yesterday with chicken wire and sphagnum, but would like to try a few methods to see what works best for me and the plant.

edited spelling

This message was edited Nov 15, 2009 9:33 PM

Here is the plant when it gets mature.

Great photo Dave! The Epipremnum grow up the trees here in Florida too and I love those huge, split leaves. My next door neighbors planted a small one at the base of a Sugarberry tree and it's just starting to climb.

3jsmom, I bought my totem online, they are made from plastic pipes (like the kind used for indoor plumbing) covered in coconut fibre (I think) which has plastic wire wrapped around it to keep it in place. Probably very easy to make yourself if you can find the materials. I did try to make one from thick plastic netting filled with sphagnum moss but it looked a bit shoddy.

About the Epipremnum, I wasn't aware that the leaves split. I assume that indoor plants will never reach this stage? Does anyone actually keep them as house/garden plants in Hawai'i or are they too invasive?

Why not use a tree branch? If you live in the right area they're free!

Amazingly, stores still sell Epipremnums and other invasive vines in Hawai'i. Many folks will buy them only to find that when they put them in their gardens they become aggressive and go everywhere. Our lowland forests are heavily invaded by Epipremnums, Philodendrons, and Syngoniums.

Some folks do keep them as houseplants here. One of the more interesting plants I've seen is an Epipremnum growing out of a fish tank with live fish (guppies) and trained all around a living room. No soil and healthy.

For Epipremnum to get large (stems to a 4 in. diam / leaves to 3 ft.) it must be allowed to become a hemiepiphytic vine, crawling across forest floors full of organic materials and up trees. They will go 100 ft. up trees in a rainforest, and that is where their leaves will get mature and pinnately divided, and they will only produce flowers up in a tree.

For Epipremnum to get big as a houseplant, train it on something (tree branches or your "totem") that its' stem can throw roots into and regularly water the stem with a low analysis organic liquid fertilizer such as Liquid Seaweed ("Maxicrop"). Liquid Seaweed is almost a perfect food for the vine as it has more potassium than other nutrients and that will encourage stem growth. For the leaves to get large, the stem must get big.
When growing tropical vines such as Epipremnum, Philodendron, & Syngonium, think stem growth! For the foliage to be healthy & happy, the stem must be happy. The stem is the heart of the plant!

Aloha, Dave

Dave, in a previous post about my Epipremnum, you suggested that I put some fertilizer in the water that I use to mist the leaves and I will do this from now on. I was wondering if you are aware of any other house plants that would benefit from foliar feeding? Also, I do keep the totem/moss pole moist by spraying but I never thought to do so with liquid fertilizer added! Thanks again for some great advice and information.

Paul.

Most plants will react positively to foliar feeding. Make sure that it is more diluted than the recommended amount for soil drenching.

It is good to get the support for your Epipremnum moist with liquid fertilizer, as in nature it receives a large amount of its' nutrients in the form of runoff (tea) from trees. It will help to allow the vine to sink roots into its' support, which will help the plant get bigger.