LemonBonsai
Shohin
I make sure my jade and dwarf jade have dry spells where I dont water them. I just repotted my dwarf jade and waited a couple days to water it. Its in recovery right now
Grapefruit Tree
- Thread starter LemonBonsai
- Start date
LittleDingus
Omono
Lol...whoops!
In that picture of my lime tree, there is a smaller white pot that is a flying dragon orange...so two citrus trees. The edge of rep pot contains a chunk of jade plant from a 30 year old plant. In the right corner you can see some of the trunk. The edge of leaves to the left of the red pot are leaves from desert rose. The tan pot in the left corner contains a 20 year old saguaro. So my little citrus are surrounded by succulents! While the succulents are in active growth they get the same water the citrus do!
The cacti and the jade are even in the same big box store cacti potting mix that the citrus are in. The desert rose are in Napa 8822.
The trick is that "as long as they are in active growth" they get the same water. As soon as the nights start cooling and succulent growth starts to halt, I switch over to the "water when squishy" method...I only water them when the leaves start to lose turgidity. For the cactus and rose that don't have leaves, I don't water them at all all winter. The Jade usually needs a glass of water about once a month during the winter.
I don't suggest this practice for beginners! I did a 10 year experiment with my saguaro where I watered one frequently and one "by the book". I still have both cacti though I gave up the experiment a long time ago. The one that got water grew more than twice as fast as the one that was only watered when dry. After that experiment, I was less concerned with over watering while in active growth. I am crazy paranoid about the soil turning muddy though! I repot more frequently to keep the soil fresh and free draining.
Sorry! Way off topic for a thread on grapefruit!!
LemonBonsai
Shohin
Thats ok
I dont mind off topics especially since I have succulents in training for bonsai as well
LemonBonsai
Shohin
How long do you leave your grow light on for in the winter?
LittleDingus
Omono
My house has a tall walkout basement. Both the basement and first floor are walls of floor to ceiling windows that face south east. The citrus just get window light...but with the tall windows they get much more light than normal windows.
The cacti get the same window light. The jade sits in a dark north west window. It doesn't grow much in the winter so deals with the low light well enough. The leaves do darken to a deep green since the light is not bright enough to burn chlorophyl. The desert rose go leafless so sit on a dark shelf most of the winter. My orchids and seedlings sit in a normal sized SW window under lights that run 12 hours in winter.
My daughter grows many more succulent and lithops than I do. Many of hers are in the tall basement windows but the ones she has in her room are in a NW window under lights. I think she runs them 12 hours on a timer as well.
LemonBonsai
Shohin
Thats good I asked cause I was planning on doing 6
im totally new to winter plant growing haha.
LittleDingus
Omono
Thats good I asked cause I was planning on doing 6
If all they have is the light (I don't see any nearby windows in your pic) they probably need way more than 6 hours!
What you're really after is "integrated flux" or the total number of photons that strike a leaf.
Hopefully, this doesn't come across as too condescending and I may be oversimplifying some of the details, but basically, if the optimal light exposure for the plant is 1000 photons (made up number!) those can be received in many ways. The plant can receive all 1000 at once...then be dark the rest of the day. It can receive 100/hour for 10 hours and be dark the rest of the day, receive 42 per hour for 24 hours and never be dark, etc...
All at once is not good: leaf burn! 24 hours constant is also not good...but not as bad as you might think. Plants do need darkness for the "dark reaction" part of making sugars and day length can influence behaviors though many behaviors we associate with day length are actually temperature responses. Anyway, the point is that somewhere between leaf burn and constant exposure is a happy place most plants can tolerate if it means getting a more optimal number of photons.
I have a flux meter (instantaneous intensity only...no consideration for PAR or integrated flux like a PPFD meter). I've used it to measure and what intensity my windows lose. It's about 50% That is if I set my meter on the floor just inside my sliding glass door, then take a reading with the door closed and another with it open. My windows cut out ~50% of the measurable sunlight. A rough back of the envelop calculation says that if my plants get 6 hours of direct light outside the window, they need 12 hours to get the same number of photons inside the window. The same basic _very rough_ calculation can tell you roughly how long to run lights. For LED systems that are blue/red only, the calculation is even rougher because flux doesn't care about color. 1000lux in blue/red light are are more efficient for photosynthesis than 1000lux spread across white light.
In practice, I took some rough guesses and tried it for a while and observed my plants. I had a coastal redwood that I bleached entirely of green early last fall because of too long of light. It came back fine in the spring but I stopped running those lights for nearly as long as I calculated they might need to run!
Considerations on the "how long is too long" get tricky depending on whether or not your plants are triggered by day length at all. I see you have a phal. Phals are usually considered "short day" plants that need longer nights to bloom. That's where things get tricky. Many plants...phals in particular...aren't trigger by day length so much as by temperature. I have phals grown solely under LEDs for 12-14 hours per day as the only source of light. They bloom fine as long as I give them cool enough nights. It doesn't seem to bother them that the light cycle hasn't changed at all...just that the temperature cycle has.
Succulents are great at signaling if they are happy with the amount of light! If you can run your lights long enough that your jade are lighter green, do it! If you can run them long enough to tinge any of your succulents with those reds and oranges, do it! At least til the point that your citrus leaves start looking too pale. If your succulents are starting to etoliate and/or darken in color, it's doubtful you're giving enough light to the citrus.
Honestly, since you have the succulents as a canary of sorts, I'd error on running the lights too long and cut back if you start noticing problems. LEDs run cool and your house is likely reasonably cool. You're not very likely to burn anything and if you do, it will be the crown first and easy to catch and adjust for. Too little light leads to long slow deaths that are sometimes hard to notice coming
hinmo24t
Masterpiece
citrus actually prefer drier soil too
i run a tower fan oscillating on 1 after work until the next morning
good to stir the air and reduce mildew chances with misting or humidity in air
i run a tower fan oscillating on 1 after work until the next morning
good to stir the air and reduce mildew chances with misting or humidity in air
LemonBonsai
Shohin
Ok good to know. I will start at 12 hours a day starting tomorrow and see how everything looks. I will use my succulents as a gauge!If all they have is the light (I don't see any nearby windows in your pic) they probably need way more than 6 hours!
What you're really after is "integrated flux" or the total number of photons that strike a leaf.
Hopefully, this doesn't come across as too condescending and I may be oversimplifying some of the details, but basically, if the optimal light exposure for the plant is 1000 photons (made up number!) those can be received in many ways. The plant can receive all 1000 at once...then be dark the rest of the day. It can receive 100/hour for 10 hours and be dark the rest of the day, receive 42 per hour for 24 hours and never be dark, etc...
All at once is not good: leaf burn! 24 hours constant is also not good...but not as bad as you might think. Plants do need darkness for the "dark reaction" part of making sugars and day length can influence behaviors though many behaviors we associate with day length are actually temperature responses. Anyway, the point is that somewhere between leaf burn and constant exposure is a happy place most plants can tolerate if it means getting a more optimal number of photons.
I have a flux meter (instantaneous intensity only...no consideration for PAR or integrated flux like a PPFD meter). I've used it to measure and what intensity my windows lose. It's about 50% That is if I set my meter on the floor just inside my sliding glass door, then take a reading with the door closed and another with it open. My windows cut out ~50% of the measurable sunlight. A rough back of the envelop calculation says that if my plants get 6 hours of direct light outside the window, they need 12 hours to get the same number of photons inside the window. The same basic _very rough_ calculation can tell you roughly how long to run lights. For LED systems that are blue/red only, the calculation is even rougher because flux doesn't care about color. 1000lux in blue/red light are are more efficient for photosynthesis than 1000lux spread across white light.
In practice, I took some rough guesses and tried it for a while and observed my plants. I had a coastal redwood that I bleached entirely of green early last fall because of too long of light. It came back fine in the spring but I stopped running those lights for nearly as long as I calculated they might need to run!
Considerations on the "how long is too long" get tricky depending on whether or not your plants are triggered by day length at all. I see you have a phal. Phals are usually considered "short day" plants that need longer nights to bloom. That's where things get tricky. Many plants...phals in particular...aren't trigger by day length so much as by temperature. I have phals grown solely under LEDs for 12-14 hours per day as the only source of light. They bloom fine as long as I give them cool enough nights. It doesn't seem to bother them that the light cycle hasn't changed at all...just that the temperature cycle has.
Succulents are great at signaling if they are happy with the amount of light! If you can run your lights long enough that your jade are lighter green, do it! If you can run them long enough to tinge any of your succulents with those reds and oranges, do it! At least til the point that your citrus leaves start looking too pale. If your succulents are starting to etoliate and/or darken in color, it's doubtful you're giving enough light to the citrus.
Honestly, since you have the succulents as a canary of sorts, I'd error on running the lights too long and cut back if you start noticing problems. LEDs run cool and your house is likely reasonably cool. You're not very likely to burn anything and if you do, it will be the crown first and easy to catch and adjust for. Too little light leads to long slow deaths that are sometimes hard to notice coming
LemonBonsai
Shohin
yes I plan on getting a fan within the next few days. I do mist my citrus so its a need for sure
LemonBonsai
Shohin
Well heres my fan. Ended up buying an oscilating one but then I found this one in the garage. Draws about 3 watts haha so costs less to nothing to run. Really quiet as well 
LemonBonsai
Shohin
Anybody know what this problem is? There are 5 or 6 leaves with this kind of discoloration. All are older leaves. And ive had one or two older leaves get yellow and die naturally but the pattern of discoloration looks odd to me. I just switched from 12 hours of light a day to 16 yesterday because I noticed a few leaves were looking dull green.
smjmsy00
Yamadori
this may sound counter intuitive, but I've read that those symptoms could be due to too much light. I was having issues with a dwarf orange I had indoors over the winter... switched from 14 to just 10 and it started to improve.
LemonBonsai
Shohin
Ok this gives me hope because I was doing some more searching in the tree and this is what I found
The one I am pinching was over top of the leaf that is centered in the picture. Almost like a tan line. Weird but I also just scheduled my light to be on 10 hours a day so hopefully it improves. Thanks for the reply!
I have kept an orange and lemon with my hibiscus in a southern exposure with no additional light and they do fine, even flower and set fruit. I do have grow lights for my tropical trees, but my patio plants don't get any special treatment.
LemonBonsai
Shohin
Interesting. My plants are near a window but I was just suprised that 12 hours of light it didnt like since during the summer it was getting 16 to 18 hoirs of sunlight on my benches. I will see how 10 hours treats it and hopefully see some improvment from there
smjmsy00
Yamadori
I think the main point of the article I read this on is that "as much light as possible all the time" produces net-negative results, which I think is reasonable.
LittleDingus
Omono
When growing under lights...especially LED...the heat that does the "obvious" damage isn't always there. That does NOT mean you aren't killing chlorophyll. Especially if you have blue only LEDs in the system!
Light always kills some fraction of chlorophyll. More intense light burns more quickly. Less intense light burns more slowly. You're trying to ride the edge of as intense a light you can have but burn chlorophyll slow enough that the plant can regenerate it as needed.
Think of it this way. 1,000,000 lumen (made up number) in a single burst then darkness for 10 days will still burn the leaf. 1 lumen per second over 1,000,000 million seconds won't show noticeable damage. Roughly the same number of chlorophyll molecules were destroyed either way (ignoring a lot of fringe effects!) but when delivered over sufficient time, the plant can keep up with generating more.
If the light is significantly too intense for the plant, cutting hours won't help. Stick a tender seedling in direct sun for an hour may cause enough damage that 23 hours of darkness can't repair it!
There are a lot of references that say you cannot give too much light when growing indoors. In my experience, that is simply not true. Especially if you have blue only LEDs somewhere in your light supply!
Last winter I burned out all the chlorophyll on one of my coast redwoods the light was so intense! The redwood had sat in full sun all summer from dawn til roughly 4PM. I moved it into a grow tent in the garage under an LED light for the winter. I measured the lux from the grow light with a meter and compared it to direct sunlight. Direct sunlight can top 100,000 lux in my yard. I was getting less than 40,000 lux in my grow tent. Within 2 weeks, the coastal redwood directly under the light panel (~12" from panel to canopy top) was almost completely brown! I ran the lights 12 on and 12 off and measured them at half the flux as full sun and still burned out all the chlorophyll in that tree! It sat brown all winter long until it warmed up enough in the spring to start growing again. Then those brown leaves greened right up. I really wish I would have taken pictures...but I thought I killed the tree and only kept it because the needles were still soft and not dry.
Blue LEDs burn up chlorophyll pretty quick! My habit now when I bring things in is to start with what I think is too much light and be hyper vigilant. When I see that I'm burning chlorophyll, I cut back intensity (not duration). It's easier to start with too much and cut back than start with too little and increase. The plant can tell you pretty quickly when it is getting too much light (as yours is doing) but it can take quite a while for it to tell you it is getting too little. Leaf color can tell you a lot if you pay enough attention. But too little light often goes unnoticed until the next growth flush when the growth is etioliated.
LemonBonsai
Shohin
I see so your saying that it would be better lets say to keep the light on for example 16 hours but 24" off the canopy then 10 hours 12" off the canopy?
LittleDingus
Omono
It's never that simple
Leo mentions another piece of the equation in your other thread:
Weird?
To much light? For context this is a grapefruit tree. I have a 175 watt LED grow light. Ive been trying it at 12 hours a day and it was around 6 to 8" away from the light. The reason why I ask is because online, it says 18 hours of light is ideal for indoor plants. And I am getting these...
Tempretature! There's also a dark reaction that plants need to process the starches and sugars made from photosynthesis. Season also comes into play...most plants naturally go dormant during certain seasons.
In the case of my coast redwood that I burned all the chlorophyll out of, the tree was in dormancy because the temperatures were low. It made no effort to replace it's burned out chlorophyll until the temperatures rose. Then it greened right back up to normal! Man I wish I would have photographed that! It's not much different that a lot of conifers in the winter, though. Many of them don't produce chlorophyll below certain temps so do brown out in the winter and regreen in the summer.
For any given species, there is a light intensity that is too much. Some plants are full sun. Others prefer shade. You don't want to exceed that max instantaneous intensity or you risk causing irreparable damage to the plant tissues. My experience with citrus (key lime mostly) is that those leaves of yours will be permanently discolored and will drop sooner than they normally would have. There's too much damage for them to recover fully.
You can avoid that with lower intensity...move the lights further away.
Moving into winter, there probably is not a reason to increase duration beyond 10-12 hours *if* you can muster the high end of the intensity range the plant can handle for that entire duration. That's close enough to what they get in nature they plant will be happy and optimized to use all that energy. If you *can not* manage the high range of the intensity, you *can* compensate some for lower intensity by increasing duration.
Even at lower intensities, there is an amount of integrated flux (photons over time) that the plant cannot handle. Photosynthesis just makes some raw organic products. Those are not directly usable by the plant and need to be processed in a secondary reaction: the dark reaction or Calvin cycle. The dark reaction processes the raw photosynthetic products into sugars the plant can use. Contrary to the name, the dark reaction can occur during the day
It's the "dark reaction" because it does not require light to work. It is, however, also a limiting reaction on how much flux a plant can reasonably use per period of time. "Extra" flux beyond what the dark reaction can process doesn't do the plant much good. So, may as well turn out the lights Much of light technology...especially LED technology...is driven by cannabis. That's where the money is
When you get into it deep enough, you will see growers do things like increase CO2 levels to help drive the dark reaction and use up the "extra" photosynthetic energy. I'm not a grower or user so I don't know the details of those bits beyond what I read on web sites when shopping for my lights. My personal opinion is that, for bonsai, those optimizations aren't worth the effort to achieve the absolute best growth possible. Getting near the maximum natural rate is plenty good enough. There are downsides to too rampant of growth too!My personal habits are to aim for the high end of what the plant can handle and observe it obsessively and reduce if needed. Plants generally respond to too much light faster than too little if you know what to look for. You could have caught your discolored leaves much sooner had you known what to look for. Don't beat yourself up over that! Now you know
While I believe the damage done to those leaves is permanent, the leaves are likely functional enough to keep the plant alive until it's next flush if you lower the intensity enough to prevent further damage. Don't give up if the tree gives up on those leaves before then, however. Likely the tree will try to keep them at least until the next flush has started if it can.
