Germinating Old Tomato Seeds, Reloaded

Have you ever found a pack of tomato seeds from a year or two ago and wondered if you could germinate those seeds and get them to grow?  If you've ever had this happen, the answer is definitely try it!

Yesterday, I uncovered some seeds that I thought were lost to time.  One was a tomato I had been breeding myself; another was a commercial packet that contained seeds that did not match the variety.  It was from a highly respected seed firm, so the tomatoes were either 1) a mis-labeled pack or 2) crossed seeds.  I've had crossed seeds before from a commercial pack, and it's always exciting to see what might grow out.

How old are these seeds? They've been patiently waiting for 5 years!

How Long Do Tomato Seeds Last?

I've had this happen in the past, and I've successfully germinated seeds that I had for 10 years (see a previous post on seed germination) .  So, I'm thinking that because the seeds were in a cool, low-humidity location, my 5-year-old seeds should germinate OK.

I don't expect a 90% rate -- probably more like 70 to 75%.   But hey, I planted 8 seeds of each of the two packets, so even if I get just one or two good, sturdy plants from each, I will be thrilled.  :)   (More is better, though, so I can select the healthiest plants to work with.)

Germinating Old Seeds

Older seeds being germinated, along with some fresh (new) seeds.

Older seeds being germinated, along with some fresh (new) seeds.

Because I want the seeds to have the best possible chance, I got together the following:

With the scissors, I cut slits in the bottom of the paper cups (for water drainage).  I filled them to the top with the seed-starting soil and placed each cup in the windowsill greenhouse.  When all the cups were filled, I took my liquid kelp mixture and soaked the soil, letting the water run out the bottom.

I let the cups stand for a few minutes, then lightly pushed the soil down.  When I was satisfied that the top of the soil was moist, I put on the soil surface 4 seeds per cup.  (Normally I'd only plant 2 per cup.)

I put a layer (maybe 3/8 inch thick) of the seed starting soil on top of the seeds and once again, lightly pressed down.

I added labels to the cups with the name of the tomato, and filled the windowsill greenhouse with enough water to come up 1/8 inch up the sides of the cups.  That would provide enough water to make the seed-starting soil moist all the way through the cup, to the top.

Put the top on the greenhouse (to keep the humidity up) and set the whole kit and caboodle on the seed germination heating pad, which would gently warm the bottom of the greenhouse, and by extension, the soil and seeds.

 How Long Will it Take?

Good question!  Normally it takes anywhere from 3 to 10 days to germinate tomato seeds, with about 5 days being average.  Given that these are older seeds, I don't expect to see signs of germination for 5 days at the earliest, 7 days on average.  Therefore, I wait impatiently.  ;)

Container Gardening and Tomatoes

Container gardening and tomatoes really do go together.  After all, you will still give the plant what it needs -- good soil, plenty of water, fertilizer (organic or not) and lots of sunshine.

You'll just be doing it in a different place.

Containers 101

You can't just grab any old container and stick your tomato plant in it -- as the old saying goes, "size matters".  You need to consider the size of the plant versus the size of the container.  Typically, the container measurement will be in gallons.

Determinate Tomatoes in ContainersFor a determinate tomato, you can usually get away with a 5-gallon container, although a 7 gallon is nicer, if you can get one.  Since determinate tomatoes have a limited lifespan, they are usually smaller -- and sometimes a lot smaller.   For the itty-bitty plants, you could even use a 3 gallon pot.  In the photo on the right are three of the smaller determinate tomatoes, which will only make it to about 2 feet high.  I have them in 5 gallon containers.

(For my bigger determinants I'll go to 10 gallon containers.)

When it comes to the indeterminate plants, container size does make a difference, between a decent enough harvest and a good harvest.  Most indeterminate plants are pretty darn big (I've had Brandywines grow to 6 feet tall and 5 feet wide when I let them), so your container needs to reflect that.

For these hefty plants, I use containers anywhere from 15 gallons (for the smaller ones) up to 25 gallons for the Brandywine and Kellogg's Breakfast tomatoes.

The Dirt on Soil

One of the downsides of moving to an all-container garden is that I have to buy a lot of soil.  Nope, I can't just shovel what's on the ground into my containers.  For one, I'd have a lot of big holes in the yard, LOL.  Second, it wouldn't be great soil for the most part.  My compost pile won't fill all the containers -- what's a gal to do?

And that is to drive on down to the lawn and garden center and buy lots of bags of compost and potting soil.  And when it turns out I made a bad choice in potting soil, I have to turn around and buy some perlite, vermiculite and/or sphagnum moss to amend my bad choice.

And when I get all those (very heavy) bags home, I still have to get that soil into the containers.  So yeah, it's a pain to move from in-ground to container gardening all in one fell swoop.  But if you're just trying out a couple of containers to get your feet wet, it's really not bad at all.

What's in Your Potting Soil?Celebrity Tomato

I have learned that not all bags labeled potting soil are created equal.  Some are really nice, others not so much.  What you have to remember is that your plants need to be able to drink and breathe.

Have you ever watered a planter that was filled with sand?  You know that maybe 15 minutes after watering it, the soil is dry again.  This means you need to increase the water-holding capacity of sandy soils.

What about a clay soil -- water it, come back tomorrow and it might still be "clay soup".  In this situation, you need to increase the drainage capability.

So, compost is first on my list of "necessary ingredients" in a good potting soil, because it can both increase water-holding for sandy soil, and help with drainage on clay-based soils.  However, compost alone might make the soil too heavy.  Enter perlite, which lightens the soil, to give the roots breathing room.

(BTW, perlite is a natural substance, as are its comrades vermiculite and sphagnum moss.)

My current favorite ready-made potting soil is from Vigoro, in the orange bags labeled as organic.  Very nice consistency, if a bit on the pricy side.  I don't have to add anything to it -- just pour it into the container and plant away!

Surprisingly, Miracle-Gro's potting soil leaves a lot to be desired -- it's very heavy and the bags I got were full of sticks (not my idea of proper drainage).  I like most of their stuff, but the potting soil is low on my "buy again next time" list.  I have had to add perlite and sphagnum moss to lighten it up some.  Plus, I am not all that crazy about all the fertilizer they include in it.

Mixing Your Own

I think I'll stop for now, since this has gotten fairly long, and write up a separate entry for ideas on mixing your own potting soil.  So until next time -- keep on growing!