Preventing leggy seedlings

honu · February 22, 2007

Just thought I'd share something interesting I read on preventing leggy seedlings...
An excerpt from ATTRA publication by Lane Greer, updated by Katherine L. Adam, "Plug and Transplant Production for Organic Systems":
"Brushing is a kind of mechanical conditioning whereby the grower uses a tool... to brush the plant tops and reduce their height....Researchers at Cornell studied the best ways to brush plants. They used a piece of polystyrene foam on tomato seedlings and found that ten strokes a day was enough to reduce the seedlings' ultimate height by about 20%.... For the tomatoes, they found that 10 to 20 daily stokes were enough for height control, that there was no difference between morning and afternoon brushing, and that brushing did not affect yield. The best time to begin the brushing treatment was the first or second true leaf stage. Beginning later resulted in leaf damage.... The authors concluded that brushing is an effective method for controlling tomato and pansy plant size....Cucurbits and eggplants respond well to brushing, but peppers are damaged by it.... Controlling temperatures is another way to control plant height.... A marked difference in day and night temperatures seems to promote internode elongation, and growers have found that keeping the day and night temperatures the same helps to prevent this from happening."

feldon30 · February 23, 2007

Most people use an oscillating fan (I will buy one for my fall seedlings), but brushing works too.

Did you brush your tomatoes today?

pbud · February 23, 2007

compared to brushing my two year old's teeth, these tomatoes are a snap! No hissy fits, no tantrums, no legs to run with...maybe I'll actually try brushing em this year.

michael johnson · February 24, 2007

I might try this brushing lark, but I am wondering exactly how it accomplishes this fact, and has this effect on the plants-very strange indeed ???,

But I will try anything once, perhaps they duck their heads down when they see the brush coming and remain short. :wink:

I once saw the shortest tomato plants I have ever seen on sale at a garden centre, they were barely three inches high of well known varieties and forming their first flower buds already, I didnt buy any because I was pretty certain that they had been treated with a dwarfing spray normaly used on crysanthemums.

feldon30 · February 24, 2007

Quote:

Originally Posted by michael johnson

I might try this brushing lark, but I am wondering exactly how it accomplishes this fact, and has this effect on the plants-very strange indeed ???

I'm not sure why brushing tomato plants, which has been done for over a century, is "very strange indeed".

I'm fairly certain that any stress on the stems will encourage them to grow thicker.

ZBQ · February 24, 2007

Quote:

Originally Posted by feldon27

Most people use an oscillating fan (I will buy one for my fall seedlings), but brushing works too.

Feldon,
Tell me more about this oscillating fan technique. Sounds like something I would like to try.

Suze · February 24, 2007

Speaking of using an oscillating fan, although it is not a 'must have', I am a big believer in using one turned all the way up on 'high' from the very beginning (after germination).

The few times I've not used a fan, seedlings were not nearly as stocky and sturdy. I put the fan on the timer along with the lights -- for 16 hours/day. Another benefit is that it helps keep the surface of the soil(less) mix drier, reducing chances of damp off.

RDUN · February 24, 2007

I've had an oscillating fan on my seedlings this spring as well...on the same timer as the lights. I started it about a week after germination. I've only had mine on low and set back about 4 feet from the seedlings. I don't know if I'd dare put it on high because it seems like the low setting keeps them swaying pretty good. My fan is a regular table fan. (12" maybe). My seedling are quite stocky and sturdy compared to last fall. (See Feldons Houston post for pictures)

I think the fact that I can easily keep them at 60-65 degrees in the spring helps to keep them from getting too tall. I wasn't too interested in keeping the AC set at 65 last August when it was 100 degrees here. The utility bills were high enough already.

dcarch · February 24, 2007

It is not easy to find small oscillating fans.

Auto supply stores and boating supply stores sell small 6" ocillating fans. The only thing is that you need to find a 12V dc power supply to run it. You can run the fan at 6v to get a gentler breeze.

dcarch

feldon30 · February 24, 2007

My problem is the fan needs to be on a 4' pole since my seedlings are on top of a table that I made out of plywood which is resting on top of a bathroom vanity.

dcarch · February 24, 2007

Quote:

Originally Posted by feldon27

My problem is the fan needs to be on a 4' pole since my seedlings are on top of a table that I made out of plywood which is resting on top of a bathroom vanity.

Something like this?

http://cgi.ebay.com/28-Inch-3-Speed-...QQcmdZViewItem

dcarch

Suze · February 24, 2007

Quote:

Originally Posted by feldon27

My problem is the fan needs to be on a 4' pole since my seedlings are on top of a table that I made out of plywood which is resting on top of a bathroom vanity.

Any standard one on a pole should be fine, as you can also angle the fan itself upward or downward.

Be sure and pick one up well before seed starting time, as fans tend to be a seasonal item even in Texas. I was reminded of this fact because I had broken my fan, and threw it away before the move. Had to go to several stores before I finally found one.

feldon30 · February 25, 2007

dcarch,

I don't know if there is any advantage to using those newer style fans on seedlings.

I don't really know if anyone has done the research. As long as I can get it 4' off the ground, I'm happy.

tylenol · February 25, 2007

Hairdryer's work very well. They may not oscillate, but can be positioned or set up on the table or bench to blow across the the tops of the plants. Of course the heat and air speed settings are important or unnecessary, but most have adjustments or can be disabled all together. The cost is considerablly less than using "room" type fans.

Rob

David52 · February 25, 2007

It can be an effort if there are lots of plant trays, but I have found that if I take them out doors on a breezy day and leave them for a few hours, the combination of direct sun and the breeze will toughen the stems up considerably. Its a bit of an art, waiting for a day with enough clouds that they won't get sunburned, and enough of a breeze so they get moved around quite a bit but not blown all the way to Kansas. However, just once is enough to do it, and they grow up thick and strong.

I do about 30 trays, and thats pretty much all I would want to use this method for.

February 22, 2007	#1
honu Tomatovillian™ Join Date: Feb 2006 Location: Hawaii Posts: 270	Preventing leggy seedlings Just thought I'd share something interesting I read on preventing leggy seedlings... An excerpt from ATTRA publication by Lane Greer, updated by Katherine L. Adam, "Plug and Transplant Production for Organic Systems": "Brushing is a kind of mechanical conditioning whereby the grower uses a tool... to brush the plant tops and reduce their height....Researchers at Cornell studied the best ways to brush plants. They used a piece of polystyrene foam on tomato seedlings and found that ten strokes a day was enough to reduce the seedlings' ultimate height by about 20%.... For the tomatoes, they found that 10 to 20 daily stokes were enough for height control, that there was no difference between morning and afternoon brushing, and that brushing did not affect yield. The best time to begin the brushing treatment was the first or second true leaf stage. Beginning later resulted in leaf damage.... The authors concluded that brushing is an effective method for controlling tomato and pansy plant size....Cucurbits and eggplants respond well to brushing, but peppers are damaged by it.... Controlling temperatures is another way to control plant height.... A marked difference in day and night temperatures seems to promote internode elongation, and growers have found that keeping the day and night temperatures the same helps to prevent this from happening."

February 24, 2007	#9
dcarch Tomatovillian™ Join Date: Jun 2006 Location: NY Posts: 2,618	It is not easy to find small oscillating fans. Auto supply stores and boating supply stores sell small 6" ocillating fans. The only thing is that you need to find a 12V dc power supply to run it. You can run the fan at 6v to get a gentler breeze. dcarch __________________ tomatomatomatomatomatomatomatomatomatomatomatomato matomato tomatomatomatomatomatomatomatomatomatomatomatomato matomato tomatomatomatomatomatomatomatomatomatomatomatomato matomato

February 25, 2007	#15
David52 Tomatovillian™ Join Date: Jul 2006 Location: SW Colorado Posts: 74	It can be an effort if there are lots of plant trays, but I have found that if I take them out doors on a breezy day and leave them for a few hours, the combination of direct sun and the breeze will toughen the stems up considerably. Its a bit of an art, waiting for a day with enough clouds that they won't get sunburned, and enough of a breeze so they get moved around quite a bit but not blown all the way to Kansas. However, just once is enough to do it, and they grow up thick and strong. I do about 30 trays, and thats pretty much all I would want to use this method for. __________________ That last tomato, dear? What last tomato? That stain on my shirt collar? Um, er, lipstick.

February 23, 2007	#2
feldon30 Tomatovillian™ Join Date: May 2006 Location: Rock Hill, SC Posts: 5,346	Most people use an oscillating fan (I will buy one for my fall seedlings), but brushing works too. Did you brush your tomatoes today?

February 23, 2007	#3
pbud Tomatovillian™ Join Date: Mar 2006 Location: Bay Area Posts: 173	compared to brushing my two year old's teeth, these tomatoes are a snap! No hissy fits, no tantrums, no legs to run with...maybe I'll actually try brushing em this year.

February 24, 2007	#4
michael johnson Tomatovillian™ Join Date: Jan 2006 Location: UK. Posts: 960	I might try this brushing lark, but I am wondering exactly how it accomplishes this fact, and has this effect on the plants-very strange indeed ???, But I will try anything once, perhaps they duck their heads down when they see the brush coming and remain short. :wink: I once saw the shortest tomato plants I have ever seen on sale at a garden centre, they were barely three inches high of well known varieties and forming their first flower buds already, I didnt buy any because I was pretty certain that they had been treated with a dwarfing spray normaly used on crysanthemums.

February 24, 2007	#7
Suze Tomatovillian™ Join Date: Jan 2006 Location: Texas Posts: 3,027	Speaking of using an oscillating fan, although it is not a 'must have', I am a big believer in using one turned all the way up on 'high' from the very beginning (after germination). The few times I've not used a fan, seedlings were not nearly as stocky and sturdy. I put the fan on the timer along with the lights -- for 16 hours/day. Another benefit is that it helps keep the surface of the soil(less) mix drier, reducing chances of damp off.

February 24, 2007	#8
RDUN Tomatovillian™ Join Date: May 2006 Location: Fort Worth, TX Posts: 78	I've had an oscillating fan on my seedlings this spring as well...on the same timer as the lights. I started it about a week after germination. I've only had mine on low and set back about 4 feet from the seedlings. I don't know if I'd dare put it on high because it seems like the low setting keeps them swaying pretty good. My fan is a regular table fan. (12" maybe). My seedling are quite stocky and sturdy compared to last fall. (See Feldons Houston post for pictures) I think the fact that I can easily keep them at 60-65 degrees in the spring helps to keep them from getting too tall. I wasn't too interested in keeping the AC set at 65 last August when it was 100 degrees here. The utility bills were high enough already.

February 25, 2007	#14
tylenol Tomatovillian™ Join Date: Jan 2006 Location: Chatsworth,Calif. Posts: 117	Hairdryer's work very well. They may not oscillate, but can be positioned or set up on the table or bench to blow across the the tops of the plants. Of course the heat and air speed settings are important or unnecessary, but most have adjustments or can be disabled all together. The cost is considerablly less than using "room" type fans. Rob