what size to re-pot and next soil?

[Ms. Jitomate]

I currently have 144 small tomato plants with 4 true leaves in 3" by 3" plastic grow bags in approximately 3" to 4" of starting medium. The plants are 2.5 to 3.5 inches right now and are 5 weeks old. I need to transplant them because I am donating them for a plant sale for my daughter's school. One gallon pots seem too expensive because of the amount of soil needed. What would be a better size? And what would be the least expensive potting soil for this next transplant into these pots? I was thinking Euro pots 17 cm with 6 5/8" diameter and 6" tall sold at the greenhousemegastore.com, so that they can sell them for $4 to $5 each. Capacity is 2.588 qt. but is that filled to the top? These are seeds purchased from Heritage Tomato Seeds and Wild Boar Farms.

[huntoften]

I would use 10-16 oz plastic cups with a hole or two drilled in the bottom. Very economical and the shape of the cups make them super easy to plant.

[Tania]

When I pot up my tomatoes, I use 1 part of high quality soiless mix (i.e., Pro-Mix) and 1 part of compost. It works well for me, and I do not need to fertilize until it's time to plant them into the garden.

From 3" pots I go to 1 gal pots.

[efisakov]

At the Lowe's: Fiskars 5.25-in H x 6.5-in W x 6.5-in D Clay Plastic Pot $1.77
Check the Dollar store as well, some times I find there nice temporary pots for 50 cents or so.

[Rockporter]

I found some 1.5 gallon sand pails with a rope handle at the local Dollar Tree and they were perfect for some tomato plants I needed to save from the community garden. I used a very skinny but tall drill bit and put about 4 holes in each one. I did them in a stack and I think I got four per stack done.

I can reuse them a few times. I am not sure you want to spend $1.00 per pot, but they are the perfect solution, since you can plant the tomato plants deeply, allowing for a very strong root system.

[Hotwired]

I go to a restaurant supply house and buy 20-oz. colored cups at $2.20/hundred. They also carry 1-quart carryout containers in clear and colored at $2.99/50. If you are watering with chlorinated water, clear cups are fine. Algae growth on the inside of the cup surface from sun exposure can be a problem for plant marketability. You'll need a drain hole in the bottom. Stack 20 cups together and drill a 1/4" hole through 20 at once. That takes care of your container problem, however you will need 144 quarts or a little less than 5 cubic foot of potting soil (29.92 quarts per Cubic Foot). I use SunGro Metro Mix 360, which is $18/2.8 cubic foot bag (~84 quarts/bag). I personally would fill the cups 1/2 full, wait until they get much bigger, and then add more soil to get the roots deeper. It depends on how big you want them before selling them.

Here's my $0.06 quart carryout cup....

[Ms. Jitomate]

Thank you for your responses. Pots over $1 are not affordable. Restaurant plastic cups are doable for seedlings. In fact I like Hotwired's suggestion on drilling the holes on the restaurant cups. But I still want to go a little larger than 16 oz cups because I want them to look professional and have a healthy root system if they are going to sell them for $4 or $5. Tania, at what point do you transfer to the gallon containers?

The closest I've come to a soilless mix here in California is Sunshine Mix 4 Aggregate Plus which I was able to get for $31 a bale. I still have 2/3 of the bale left over. That's what the 3" containers have right now. I have lots of compost because I did a whole lot these past 6 months, so I like the idea of mixing both of these together, especially since my compost was free.

When you order pots, does the capacity stated mean all the way to the top? When I buy a plant in a gallon container at a nursery they are never filled all the way to the top. I also like Hotwired's method of planting the small plant in its final container and as it grows taller adding more soil. Hotwired, thank you for the calculating the conversion of dry quarts to cubic feet. That sometimes confuses me.

[casino]

I use 6 oz cups to start the seedlings using 100% pro-mix. Then when the tomatoes grow out of those cups I move them into the 16-20 OZ cups purchased from Costco and I use the same mix as tania. I/2 part pro-mix to 1/2 part screened compost. Some how the tomatoes know when they are moved into a larger container and they really take off.

My red cups from Costco need drainage holes and in the past I would drill a hole in the bottom of the cup but if the drill was dull I would not have a nice clean hole. After several damaged cups I have changed my strategy to make drainage holes in 1000 cups. I make a bond fire in the backyard. Heat up a piece of rebar red hot stack up 6 cups (bottoms up) and melt the hole instead of drilling a hole. I have 2 rebar poles red hot and it only takes seconds to make a hole and it comes out clean every time.

[Hotwired]

Originally Posted by casino

Heat up a piece of rebar red hot stack up 6 cups (bottoms up) and melt the hole instead of drilling a hole. I have 2 rebar poles red hot and it only takes seconds to make a hole and it comes out clean every time.

I'm going to borrow that idea. I've split my share of cups with dull bits.

[surf4grrl]

You can keep tomatoes in a relatively small container - I have sold tomato starts in 3"-4" pots and they have stayed in them for 18-12 weeks. It will force them to put up more top growth.

It also depends on when you're selling them (1 week versus 10 weeks)...

Remember when you pot up in bigger pots, the plant is busy making roots, not putting on top growth.

You don't want to go too big.

[nativeplanter]

Originally Posted by Hotwired

I'm going to borrow that idea. I've split my share of cups with dull bits.

On a smaller scale, a soldering iron works nicely also.

[Crandrew]

Originally Posted by Hotwired

I'm going to borrow that idea. I've split my share of cups with dull bits.

Not to mention you get the hanging chads if the drill bit is dull. I like this rebar idea.

[riceke]

I agree with Surf4grrl about not replanting them. I've raised 10" plants in 3" container's for transplanting. As long as you keep them watered and fed they should make it for your intention. Maybe give instructions with each plant on what to do with your new seedling.
You could print them out on a self stick label and attach to the plant.

[chilisauce]

Originally Posted by Hotwired

I go to a restaurant supply house and buy 20-oz. colored cups at $2.20/hundred. They also carry 1-quart carryout containers in clear and colored at $2.99/50. If you are watering with chlorinated water, clear cups are fine. Algae growth on the inside of the cup surface from sun exposure can be a problem for plant marketability. You'll need a drain hole in the bottom. Stack 20 cups together and drill a 1/4" hole through 20 at once. That takes care of your container problem, however you will need 144 quarts or a little less than 5 cubic foot of potting soil (29.92 quarts per Cubic Foot). I use SunGro Metro Mix 360, which is $18/2.8 cubic foot bag (~84 quarts/bag). I personally would fill the cups 1/2 full, wait until they get much bigger, and then add more soil to get the roots deeper. It depends on how big you want them before selling them.

Here's my $0.06 quart carryout cup....

Hey, Hotwired! Nice greenhouse! We went to school in Ithaca- great gardening mecca- we love the Plantsmen.

[Tania]

I transplant to 1 gal containers when my seedlings reach 1' tall. Until then they are in 3-4" plastic pots.