Friday, January 1, 2010

Get Growing in January

This is the second in a twelve part series for new gardeners. If you have never planted vegetables before but always wanted to, this is the series for you. Robin, who writes the blog Vegetable Matter, and I will post on the first of every month. Robin lives in Houston and I live in Boston. We will be posting about what to do in the garden that month and giving advice. So if you have always wanted that vegetable garden, but didn’t know where to start, you have no excuse. Get growing!

Growing your own seedlings

Up north we are locked in ice still. There is no outside growing going on. Even the intrepid folks who have low hoops over their garden are just hoping everything lives through the cold of January. The one place we can start to think about growing is inside under lights.

Many people buy all their transplants from the garden center. I've certainly done that in many years, but doing so limits your choices. Tomatoes might be the one exception. For instance Verrill Farm in Concord, MA might sell 30 varieties of tomato transplants every year, but they only sell a couple of kinds of peppers. So if you want anything but Cherry Bomb or Jalapeno, you are out of luck. Looking in a lot of different garden centers can improve your odds of finding the pepper you want. But if you are looking to grow a Fish pepper, for a spicy white cream sauce, you will have to grow your own.


The best way to grow your own transplants is with artificial lights. You can do transplants using the natural light on a south facing windowsill, but I've found that the transplants are more leggy and not as strong. They succumb more easily to disease.

The LEDs were getting a lot of press, but I tried them and they aren't quite ready for prime time yet. Fluorescent shop lights however are cheap and easy to get. And best of all they really work well.

You can get shop lights at hardware stores and home improvement centers. You might even have one in your basement right now. Four foot long T8 lights give you the largest bang for the buck. Shop lights come with two bulbs in them. Some are spaced a couple of inches apart. Some are closer together. You want to pick the light with the bulbs spaced as far apart as possible. In addition you want a wide reflector. Your plants will grow best if they are right under the lights and if the lights are spaced farther apart you have a wider growing surface.

Many people buy full spectrum lights. Save your money if you are only growing transplants. The cheap cool white bulbs are perfect for leafy growth. The red part of the spectrum is only needed if you want to grow flowers. So I hear the question already, "What if I'm growing marigolds which are flowering plants?" Even flowering plants do better and have more blooms in their future if you transplant them young, before they bud out. So in their youth they only need blue.

The one thing you should spend money on is replacing your bulbs every couple of years. Fluorescent lights lose brightness over time. The less bright your bulbs are the weaker your transplants will be. Every time I do it, it seems really wasteful, but your plants will thank you. If you don't like throwing out bulbs that still work, I suggest putting them on Freecycle (remember fluorescent bulbs have mercury in them and should be thrown out with the rest of the garbage, my town has a toxic waste day where you can toss things like that and they will be processed appropriately).

Shoplight being used to grow seedlings

When you set up your lights, put them on chains (they often come with chains) so you can raise and lower the lights. It is best to always keep the lights about and inch or two above the plants. If the plants start to touch they can get burned. If they get too far away the plants will get leggy. You can attach them to anything (mine are on brackets in the wall), but most people use wire shelving rack that come 4' wide. You can just hook the chain onto the top shelf and grow on the shelf below. If you need even more space you can use all the shelves.

Where should your shelves be? They should be in a room that is not too hot and not too cold. This can mean a different temperature for different crops but I have found if your room is between 60F-75F (15C-21C) almost all the crops will grow. I have mine in my laundry room which maintains a temperature of about 62F (16C). Warm weather crops (tomatoes, peppers, and eggplants) will grow just fine as transplants there, but they won't germinate easily at that temperature. I own a heating mat and use it to make sure they germinate and remove it once they are up. If you don't want to spend the money on a heating mat, you can germinate the warm weather crops in a warm spot in your house. The top of the refrigerator often fits the bill. I've even used the back of my desk where the radiator heat comes up. Just make sure they get moved to the light the instant they pop out of the soil.

Except for onions (which bulb up due to the length of the day), you should keep your lights on for about 15 hours a day. I heartily recommend a timer so you don't forget to turn them on and off. Don't leave them on all night long as plants need a rest from the light.

Growing mixtures

You can't grow seedlings in your typical garden soil. Your garden soil is too heavy and has lots diseases and insect pests. Young seedlings are prone to damping off disease. Most people buy a sterile seed starting mix from the local garden center or hardware store. I heartily endorse the behavior for first time growers even if I don't always do it myself (mostly I make my own mix).


Once you have your soil, you have to find something to put it in. The only requirement is that it is deep enough (for many plants 2" is plenty) and it has holes in the bottom so it can drain well.

Onions growing in commercial cell packs

Commercially you can buy cell packs and trays. They have little dividers between plants so their roots don't get tangled. Plants find transplanting stressful (though different plants take the shock differently) and this separates the roots from one another to reduce the stress. You can also find peat pots and jiffy pots that reduce the stress even more. With these you don't even remove the plants from the pot. You plant them pot and all. I find them a bit on the expensive side. Peat pots I find have another problem too. The compressed peat is hard for the plant roots to get through and can slow down the plants rooting into the soil itself once it is planted. In addition the pot rim can wick up moisture from the soil and dry out the plant. I've found the plants just don't grow as well as other methods.

You do not have to spend money on pots however. You can make your own. You can make flats of plants (where the roots do grow together) from things like plastic clam shells from your recycle bin. You can use old cardboard boxes (but they wick water so need to be watered more often). You can use tossed plastic cups. These are all free. Once caveat is that you have to punch holes in the bottom so the water can drain out well.

A flat of newspaper pots waiting to be transplanted

Another homemade pot is the newspaper pot. Commercially they sell forms to make them quickly. In addition there are plenty of instructions online for how to make them, but you can also do it very simply like I do. I merely take a long strip of newspaper about three inches high and loop it around a bottle and use a paper clip or piece of masking tape to keep it from coming unraveled. I don't even have a bottom to the pots. I keep the soil in by compression. I compress the soil firmly into the bottom while keeping the pot down on the counter. Sometimes I lose a little dirt when watering, but mostly it stays together quite well. And once planted, the roots are instantly free to grow.

Soil blocker

Last year I started using soil block makers. Soil blocks are just compressed soil. They hold together because of the compression of the soil that has a lot of peat. They aren't as easy as other methods and have a learning curve. I found it took a while before I figured out just the right amount of water to add to the soil mix and how to get the soil compacted evenly across the blocker (I use my hands, though none of the instructions you will read will tell you to do this). In addition they are harder to water. I find bottom watering the simplest method, but you have to do it gently and not near a block so the soil from the blocks isn't washed away. Many say to use a mister to keep them moist, but my hands aren't strong enough to mist until all my blocks are moist all the way through. In addition the blockers needs a soil mix that will hold up to the blocker but drain well enough when compressed. The general advice is to make your own. I have done this and also used Fedco's Fort V potting mix. Both seem to work well though my homemade mix is cheaper. There are probably other brands that work well too, but since I haven't tried them I can't recommend them.

Soil blocks

So why would I go to the trouble of using a soil block if it is so hard? Well the best thing about a block is the it just gets planted right into the ground which means there is no transplant shock at all and the plants grow strongly as soon as they are planted. And unlike even a thin newspaper pot, there is nothing to break down before the roots can reach the soil. The roots instantly take off. So of all methods it is the hardest for the human, but the easiest on the plants. If you are interested in reading more about them is a good reference site, but remember that it is a commercial site so has a vested interest in you buying something.

Watering and Fertilization

Many people just pour water over their seedlings to water. I don't recommend this. Fungal diseases are more common when the foliage of the plants get wet. We are indoors and there is no reason to do this to your plants. I recommend bottom watering. You will need a tray that is bigger than your pots. Pour water into the tray to about an inch and then gently sink your pots. When you see the top of the soil is wet, they have been watered sufficiently and you can remove them to drain. If you have blocks you need to be even more careful and put the blocks in a tray (I keep them in one) and slowly pour in the water so the stream doesn't hit any blocks. Only pour in a bit at a time and slowly let the blocks soak it up. You don't want to get the water to high or move very fast or the soil might wash away.

Before you water again let the surface of your pots dry out. If they stay wet all the time they will be more prone to damping off and mold will grow on the surface (most surface molds are harmless so don't worry too much about them). You never want to let it get dry enough that your seedlings wilt, but they do better if they aren't constantly soggy either.

I use a soil mixture that has enough organic fertilizer in it that I never need to add fertilizer while my seedlings are growing. I find this the easiest solution. Many seedling mixes will contain fertilizer too. If your soil mix doesn't have a fertilizer then you will need to fertilize your seedlings regularly with a balanced liquid fertilizer. You can do this whenever you water. The bottle will usually have a recommendation for how much to feed, but never use more than a half strength fertilizer on seedlings and don't start until they have their first true leaves. (The first leaves on a plant are called seed leaves and usually have a different shape than the leaves that will come next, or their true leaves.)

Keep the Seedling Healthy

Plants don't like the air to be absolutely still like it is indoors for two reasons. The first is if the air doesn't circulate, damping off is more likely to kill your plants. Damping off is a generic term for a lot of different fungal diseases, but they all have the same symptoms. The plant stem either at or just below the surface rots and the plant falls over. It is less common if the soil surface is kept dry (though a dry surface will not prevent it totally). So circulating air helps keep the soil from staying damp too long. There are some home preventatives (not cures, once your plants have this kind of rot on their stem they are dead - get rid of them before they infect their neighbors). If after you sow your seeds, you sprinkle the surface with cinnamon it will help prevent the disease. Also diluted chamomile tea works fairly well, if you put it into your watering can, or if you spray it lightly on the plants.

Air circulation is good for another reason. The stems of plants that are grown in air that is very still tend to be leggier (taller and thinner). They also don't have the strength to stand up to the wind when finally put outside. If the plants are grown with air movement they will be shorter and stockier and won't be as shocked when transplanted outside. Thigmomorphogenesis is the word that botanists use for this phenomena. Interestingly enough you don't really need wind. If you pet your plants, the touch of your hand will keep the plants from getting spindly too. But a small fan works really well. You don't want one that is very powerful. Heavy wind will set the plants back, but mild breeze will help them out. I use a cheap little $10 clip on fan. I don't keep it on all the time, but turn it on for an hour or so every couple of days usually right after I water.

What Plants and How Long They Grow Indoors

Not all seeds should be started indoors. Some like bean seeds hate to be transplanted and germinate well outdoors, so why bother. If you start them inside you have to be really careful not to disturb their roots at all and they still often do better direct seeded. The following is a list of the most common of these plants: beans, peas, spinach, corn, melons, cucumbers, and squash.

Some people elect to try to start them inside for the following reasons. Some winter squash has a long growing season and if the plants aren't given a head start they won't have time to ripen (a reason only for short growing seasons). An extra early harvest is another reason. Getting the plants big enough before they are put out so the slugs don't eat them to the ground before they get big enough (the reason I do this with cucumbers). Spinach sometimes has germination issues so they start them inside. I generally recommend not growing these indoors unless you have a solid reason for doing it. They are much easier as direct seeded plants. If you do elect to grow these indoors, make sure you use a pot that doesn't disturb the roots, like newspaper pots or soil blocks.

There is a list of plants that I would never transplant. These are typically root crops: carrots, beets, radishes, turnips, rutabaga, parsnips, dill, and cilantro. Root crops (with the exception of onions that are always done as transplants or sets) just hate being transplanted and sometimes will never form a good root if you do.

Then there are the seeds that are easily grown direct seeded in the garden, but do well as transplants too. Whether they are direct seeded or grown indoors is really an issue of your climate and the timing of when you want to get crops. If I grow successions of lettuce indoors I can get the seedlings older before they need space in the garden. Then they might only need to spend a month in the garden to head up instead of two. So sometimes growing seedlings indoors is just a space saver. Some use part of the garden as a nursery bed for just this reason. If your broccoli needs an 18”x18” spot in the garden, you might not want to give it that space until it needs it. You could grow something else there until your transplants are ready. But on with the list of crops in this type: lettuce, Asian greens, broccoli, cabbage. In the north the last three are almost always grown as transplants, but I see a lot of southern gardeners direct seed these crops as they have a longer season.

The last list is a list of the plants that people almost always grow from transplants or buy from a nursery. It really isn't necessary. Tomatoes will grow quite well from seed in the garden, but usually the seasons aren't long enough to get a crop before frost (or intense heat in the far south). These are peppers, tomatillos, tomatoes, onions, and eggplant.

How long should you grow these crops in pots indoors? Maybe people will say that tomatoes need 8 weeks before transplanting. This isn't necessarily true. It depends upon how big of a pot you it is grown in. A good rule is that transplants should never get root bound. Once the roots have filled up their pot they either need to go out into the garden or they need to be given a larger pot. If you don't do this the plant will get stressed and your yield will go down. So if you are only growing them in a small pot and don't want to pot up, you need to grow them for a shorter period of time. Smaller transplants can often grow better than larger ones. For some plants once they hit a certain stage in their growth they quite working on their roots and put their energies into their leaves or fruit. If you haven't gotten your plant into the garden by then you won't get a good root system and your harvest will suffer. Peppers are cruel this way. They tell you right when you've waited too long. Once they start flowering they have gotten a bit too old. I still plant peppers that have started flowering out in the garden, but I really try to make sure they haven't started yet.

Below is how long to grow your transplants.


How long to grow in weeks

When to plant after last frost

Careful of roots

Needs heat to germinate


5 to 6



3 to 6

-2 to 0

Chinese Cabbage

3 to 6



3 to 6

-2 to 0


3 to 4

-2 to 0


2 to 3





3 to 6




3 to 6

-2 to 0


8 to 12

-2 to 0


3 to 5

-2 to 0


2 to 4





8 to 10

-2 to 0


4 to 7




2 to 3





4 to 8*




4 to 6



*I've found tomatillos a little problematic on timing. Some can germinate in a few days (like most seeds) and some can take several weeks. If yours germinates quickly the timing might be shorter, or if they are very slow they might be longer.

You will notice that some of the cold hardy plants say you can plant them at your last frost date or a couple of weeks before this date. The variable is how well you harden off your plants before setting them out. If a plant is grown indoors in a nice controlled environment than is just planted outside it can easily succumb to the harsh conditions. If you slowly acclimatize the plant to the weather the plant will learn how to deal with the temperature swings and cold temperatures. I'll talk more about transplanting and hardening off later in the year.

The other variable is how long to grow the plants. Typically the lower range is if you only give them a smaller pot to grow in, say 1 1/2” square. The second number is if you pot them up (move them to a bigger pot) to a 4” pot. I often pot up into deep newspaper pots, but however you do it the roots need more space once they fill out the pots they are in.

The plants that don't like root disturbance like the squash should never be potted up. Start with a larger pot. I use a 4” tall and 3” wide newspaper pot. You want to see at least the first true leaf before planting out, but no more than two true leaves. Shorter is often better with these types of plants.

When you pot up your plants make sure they are growing in their new pot at the same level they were growing in their old pot. Some plants will die if they are sunk too deep into the pots. The major exception is tomatoes. For tomatoes you can plant the low into the new pot. A tomato plant will put out roots all along the stem, so it only makes the plant stronger.

The last thing you need to know to calculate when you want to start your plants is your last frost date. Robin talked about this last month, but because it is so important I'm going to talk about it again.

Your last frost date is something you will learn over time. There are some wonderful charts out there that will tell you what it is, but every location is slightly different. For instance I live on a steep hill. Cold air sinks so the colder frosty air just flows right down the hill to the valley. Just a few hundred yards from my house could have a frost weeks after I have had my last one. Robin had a good link in her December post. My favorite frost chart is here. Just scroll to your state and click on it. It will bring you to a page that lists where all the official weather stations in your state are. Find the one closest to you for an idea of when last frost is. Use the average 36F degree row since frost can easily occur when the thermometer reads over 32F (remember cold air sinks and readings are usually not taken right at the ground level).

Other post in the series

Determining your growing zone and planting peas (Vegetable Matter - December)
Planning a Garden (Daphne's Dandelions - December)
Growing Lettuce (Vegetable Matter - January)
Starting transplants indoors (Daphne's Dandelions - January)
Growing tomatoes (Vegetable Matter - February)
Compost (Daphne's Dandelions - February)
Snap Beans (Vegetable Matter - March)
Peas and Spinach (Daphne's Dandelions - March)
Eggplant (Vegetable Matter - April)
Brassicas (Broccoli, Cabbage, Asian vegetables) (Daphne's Dandelions - April)
Edamame (Vegetable Matter - May)
Tomatoes (Daphne's Dandelions - May)


  1. Dear Daphne, this is one for the long term! I can imagine people coming to this post for years and years to find so much great info at one place. Kudos. It is good for non beginnings as well. I especially appreciate the chart of when to start the seeds, something that fouls up my seed starting endeavors every year. Happy New Year! :-)

  2. Thank you so much for doing this post! As a beginner this is very helpful! I'm preparing to start some cole crops indoors very soon. EG suggested now but looking at that frost date chart I think I will wait till the end of the month. My last frost date is approx. April 22(this sounds about right with what the extension office info said). and I was thinking of planting out around the first of April. So about 6 weeks before would be early to mid Feb. I've gotta get my lights bought and set up first :) BTW I started my own little gardening blog if you want to stop by and check it out

    Thanks for the information and inspiration!

  3. Thank you, thank you thank you. I am growing from seed for the first time this year and have done my research, but this post really makes it all clearer to me. I know I will be referring to this many times as I plan my seedlings.

  4. Thank you Daphne!... very timely because we are just about to embark on new crops. Happy New Year!


  5. Daphne- this is exactly the advice I needed! I was at home depot the other day looking at shop light and could not decide which ones would be best. Now I know! Great advice about the soil blockers too! I will be experimenting with soil mixes in the coming weeks.

  6. Holy awesome post Daphne!! Excellent info! Will bookmark this one for sure. I have a Florida gardening book that shows me when to plant - everything else talks about the time after the last frost, but we're not guaranteed to get frost each year so that's a tough one for us.

  7. Not only an excellent article for the beginner, this is also an excellent "reminder" for the intermediate transplant grower, such as myself. Thank you for all the thought and hard work you put into this!

  8. thank you for this! I'm planning my first real/big garden this year (not just chives, haha) and this article was very helpful on starting my seeds! I just placed my first seed order today, yay! Can't wait for your guys' future articles.

  9. Frances, thanks and Happy New Year to you too.

    Tenessa Allen, you can start earlier, but I would suggest that you have some kind of protection for the plants if you do. Remay row covers work well for this.

    GrafixMuse, good luck with your little seedlings. It is really fun to watch them grow.

    Bangchik, Happy New Year!

    Thomas, I really love my soil blockers. I just bought one size last year because I wasn't sure about them, but they grow some really nice seedlings even if they are a bit of a PITA.

    Kate and Crew, yeah for the south things are really different. You can grow crops unprotected in the winter. I hear your summer is your hard season as it can get too hot for so many things.

    Annie's Granny, you're welcome!

    LoveMeKnot Creations, good luck with your bigger garden.

  10. Great post with lots and lots of good resource information - for all gardeners. You have me Jonesing for a soil block maker now! ;D

  11. this is a lot of great info all in one spot! I've thought about getting a soil blocker but they're pretty pricy. I'm not sure it would be worth it for my small time operation.

    I like your newspaper pots though. It hadn't occured to me that you could get away without a bottom. I may try this next year as I've just ordered all my supplies for the spring.

  12. Thigmomorphogenesis ? Now that's a word you don't see very often. Nice ! :)

    Another great GG post, Daphne ! The only method I haven't used so far is soil blocking. I think I suffer from 'fear of the crumble' but I bet the blocks hold together pretty well once the roots set. They certainly are a very seedling-friendly method. Thx for the info and link !

    And Happy New Year (again) ! :P

  13. kitsapFG, I bought the 1 1/2" blocker last year. This year I'm going to get two more (the micro and the 2"). Some year I may buy the 4", but it is really expensive and my newspaper pots work about as well even if they take a lot longer to make.

    Wendy, you can make your own. If you do a web search you will find several sites that show you how. You can make them from bottles so the block would be round. I wanted one that could make multiple blocks at the same time and I liked the squares since it is more usable dirt for the roots for the space under the lights.

    Miss M, the first ones I made had crumble problems. I eventually learned to make them better and learned to be a bit careful with them when watering and moving. And Happy New Year!

  14. Great post! I spent too many hours acquiring all of that information last winter, your post will be so helpful to so many new gardeners!

    I started my peas indoors last year and will do it again. Unconventional but it does give a much higher germination rate- but I had people telling me I couldn't which was kind of funny. I also started tomatoes in Feb. this was A LOT of work, but I had June tomatoes and a great crop before late blight really took hold. I am on the fence of when to start them this year, I was following many of the Victory Garden practices (all that I just mentioned) and it was all a success, but very time consuming.

  15. Great post, thanks for all this advice. Finally I know why my seedlings are too leggy sometimes. If I move seedlings closer to window (south window, in direct sunlight) will that burn seedlings?

  16. Kelly, you can start just about anything indoors. I've even seen people start carrots inside. I think the effort involved isn't always worth it. Sometimes you sacrifice the quantity of a harvest for the earliness of the crop. But for tomatoes, they might be worth the effort to keeping alive inside for several months.

    vrtlarica, if you are growing them in a window they need to be in the direct sun in a south facing window. The sun won't burn them if they are always grown in that location. I don't usually suggest growing in a window as the light often isn't bright enough. Light doesn't get through a window as well at an angle as it does straight on and our house windows aren't tilted to accept the sun like greenhouse windows are. If you do it this way, I suggest building a reflector for behind your plants to reflect the light from the window back onto the plants so you get sun from the front and the back. A simple piece of cardboard coated with white paper or aluminum foil will do.

    BTW if you have been growing them out of the direct sunlight, moving them to the direct sun can burn the plants. They aren't used to the sun yet. You need to acclimatize the plants to the sun over about four or five days first. Start with an hour and move up.

  17. This is a very helpful post. I'm still on a learning curve when it comes to starting seeds indoors. Lots of answers here about where to put the light, what lights are helpful, avoiding disease, using fertilizer, etc. I may try to newspaper pots. I usually try to save and reuse cell packs from previous years but I always run out.

  18. Sally, I reuse the cell packs too, but as I grow more myself and buy less from the garden center, they start to run out. I used to always have enough before my favorite garden center closed. The seedlings from the other places just don't grow as well as my own.

  19. wonderful post! Thanks for helping out newbies to veg. growing.


  20. Thanks a lot for the information given. It has been very helpful.

  21. Thigmomorphogenesis!
    I learnt something new today.
    Thank you.