Seedlings growing under lights

I started some seeds today in my “plant work room” and I thought you might be interested.  I start seeds in regular plastic nursery trays that I get from a local greenhouse – and that I save from store-bought plants.  I do recycle my plant containers from year to year -  If you reuse containers like this you really should wash them thoroughly in a weak bleach solution and dry them in the sun before storing them away for reuse.  Or so I’ve heard – I might try that some day.

just planted flat

This year I’m planting in commercial soil mix, because I just don’t have any compost that is ready right now to make into home made potting soil.  Anyway, fill your containers with soil and plant your seeds at the  recommended depth.  Most of what I planted today is in the cabbage family, and needs to be about 1/2 inch deep.  I just use a finger to poke holes about that deep, drop 2-3 seeds into each one and then sprinkle with more soil to cover.  I’m using pretty small divisions – 72 plants per tray – because I plan to plant out these cold season plants under row covers or in the greenhouse as soon as they are big enough to handle.  If I thought that I would have to hold them for a while I would probably start them in larger divisions to begin with.

BTW, I am also test germinating some seeds that I saved last year – by planting 10 seeds per container to see how many come up.  Assuming that some of them germinate I can just multiply the number of seedlings by 10 to get the success rate as a percentage.  Other than using 10 seeds per container they are done exactly the same way as everything else.

Using a spray bottle to water the planted trays gives good control.

I’ve found that the least messy way for me to water trays is by misting with a spray bottle – every other method that I’ve used results in muddy water running everywhere and only a little soaking in.  Check soil moisture every day until you’re sure that it has stabilized where you want it – moist, but not dripping wet.

Note that you need to label your trays – I use recycled pieces of plastic mini blinds.

A plastic seed starting chamber like this is very handy, but not absolutely required. You will have to remove it soon after your plants emerge, but until then it helps to keep the soil evenly moist and the air warm and humid. If you don't have one of these just lay a sheet of plastic right on top until you see plants starting to emerge.

Then cover with one of these plastic domes if you have one.  If you don’t have one of these you can simply drape a piece of saran wrap over the tray, but if you do that you will have to remove it as soon as you see plants emerging from the soil.  The cover holds the moisture in so that you shouldn’t have to water again until it’s removed.

My simple grow light setup uses regular 4' shop lights and bulbs - not expensive "grow" lights.

I use plain old 40 watt flourescent shop lights to start my plants indoors and it works great.  As you can see the fixtures are just sitting on top of props that I have made out of one by six scraps, but you can use whatever you have.  You want the lights to be as close to the plant trays as is practical or your plants will grow tall and leggy.   Now that compact florescent lights are widely available you could also use those in any lamp fixture that you have.  You can easily get CFLs which are equivalent to  a 100 watt incandescent light  – should be great for a smaller operation.

Last year I built a very simple bottom heat system which has made a tremendous improvement in my success rate for starting all kinds of seeds.   If you don’t have bottom heat, then try to keep the soil as warm as possible 24 hours a day.  On top of a refrigerator or an upright freezer is a good place or on a shelf right over your water heater or a heat appliance.  The regular average room temperature of your house is probably not warm enough for best results.  The lights also won’t really work to keep the soil warm because they won’t be on 24 hours a day.  If you look at this planting soil temperature chart you will see that most plants want the soil temp to be around 80 degrees Fahrenheit for best germination.  If at all possible use some form of bottom heat.

A simple analog light timer is all y0u need for starting your own plants, but you need one that is big enough to handle the load of all of the lights that you are going to plug into it.

For good results you must have a timer to control your lights.  Erratic lighting or 24 hour day lengths will be bad for many plants.  Be sure that you use a timer which is rated high enough for the total wattage of lights that you will be using.   Set the on period to correspond with or extend the  actual  daylight hours – in other words don’t try to have your plants day and night be opposite of the real day and night otherwise ambient light will interrupt their sleep just like it would yours.  I set mine to go on at sunrise and off at about 8 PM.  I currently have the day length set for about 13 1/2 hours, but when I start planting tomatoes and peppers in a few weeks I will increase that to about 16 hours of light per day.

Once I start this process every winter I love to get out in the plant room to visit and check on my plants.  The warm moist air and the smell of clean soil and growing things along with the sun light coming through the windows really takes the edge off of winter for me.  That and a cup of coffee is a great way to start the day.   Round up some seeds and soil, and see if it doesn’t lift your spirits as well.

My humble plant work room. Really just a small well insulated room on the side of my garage with 4 windows, and a concrete floor that I don't have to worry about getting dirty. The light bench is sitting on top of 5 steel barrels full of water for thermal mass which help to moderate the temperature. You can see the rope light that powers my bottom heat there at the lower right. On the far end of the bench I have just enough counter space to pot things up. I love it.

Pay attention.  This may be the most valuable tidbit of gardening wisdom anyone ever hands you. Of course it also might not be.

When to plant – every seed packet you pick up has a little map on the back with 4 or 5 colored zones and planting dates for each zone.  Or they have cryptic advice like “whenever soil can be worked”, “after soil has thoroughly warmed”, or “after all danger of frost.”    Forget all that.  Plant when the soil is the right temperature.  Period.   Depending upon how sheltered your garden is, or if it has shade in the morning or afternoon – or if it is in a greenhouse or cold frame – those dates are just about meaningless.  But, the soil temperature will almost never lead you astray because the ground temperature changes slowly – it is slow to warm up in the spring, and slow to cool off in the fall.  Not wildly swinging with every warm or cold front.

As a general rule seeds that can germinate at a lower temperature are also more resistant to rot.

If you study this table you will begin to understand why those melons never came up – too cool/wet and they rot, too warm – they just never germinate.  You will also understand what “as soon as soil can be worked” means – a lot of things can be planted in 41 degree soil (or colder) and will just take a long time to come up unless the soil warms first like in the spring time – in which case they spring up quicker.  You can also understand this – if it will germinate in very cold soil then the plant will probably tolerate some cold spring (or even winter) weather.  So – onions, lettuce, spinach, and those which will germinate at 32 degrees can be planted any time after the weather cools down in the fall and they will basically come up when the time is right and be fine – especially if they are sheltered in a cold frame.

If you are starting seeds indoors you can see why it’s so hard to get tomatoes to come up in that sunny (but cold at night) window – those little plugs of soil do cool off quickly unlike the soil in your garden.  Those tomatoes, peppers and other warm season tropical plants will get off to a galloping start if you can consistently keep them a bit warmer – like with home made bottom heat made from rope lights.

On the other end of the chart – when it is too hot for the seeds to germinate, most plants start to stress or die from heat, especially if they aren’t kept watered.  So those cool season crops need to be planted when it is cold so that they can make a crop before it gets too hot.  Warm season crops will do great if you plant them when the soil is just barely (or almost) warm enough, and then cover them with a fabric or plastic row cover or cold frame.  Cucumbers really will come up in 3 days if you do this.

BTW, one of those digital kitchen thermometers works great for checking soil temp.   If you don’t already have a cold frame then cut the bottom off of a 2 liter coke bottle and leave it in the garden pushed into the ground like you were covering a plant with it – check the temp under that in a day or two, and you will want to get a cold frame.  Of course you can also cover your seeds with the bottom of a 2 liter bottle (or plastic milk jug) until they come up.

If you take this one thing seriously and plant your garden as early as possible, but when the soil is warm enough you’re gardening prowess will leap forward by the equivalent of 20 years of experience.  I sure wish someone had handed this to me 20 years ago!

Need planting information for something that isn’t on the chart?  Search using this customized Google search engine. Try searching for – zucchini soil temperature – for example.

Gardening Search Engine – all results are from top US Agricultural Universities.

Lettuce growing in my cold frame.

When I built my 50 dollar greenhouse over a year ago one of my goals was to be able to have something fresh to eat out of the garden or greenhouse every day of the year.  Well, it’s been about a year now, and  it hasn’t even been very hard to do.

Here is what I’ve learned so far -

Despite what you might have read, lettuce spinach and other salad greens are not really  particularly quick crops.  Sure you can have a pretty little stand of plants in about 6 weeks or so under good conditions, but  in cool weather  they don’t really get productive until they are  almost 3 months old.  Yes you can harvest a few salads out of the thinnings, but the young plants  aren’t going to yield an every day supply unless you can plant a pretty large area.

When it gets cold, growth slows way down.  However, on sunny days the temperature under glass (or plastic) is balmy, and I’ve continued to see steady growth all winter long.  What should be done in the fall is to have a lot of greens grown out as much as possible before it turns so cold that growth slows down.

It’s quite difficult to get those cool season crops to grow productively in Tennessee until late into our rather warm autumns, but once it gets to be jacket weather they do great.  Same thing in the spring – once the nights get warm they fail or go to seed.  So the easy thing to do is to seed dirrectly into a cold frame or green house in September, then seed again every few weeks all winter long and you can have fresh lettuce and spinach from  before Thanksgiving until June.  Last year I had tons of productive growth by late winter/early spring.

You can not only grow, but garden in relative comfort all winter long in a simple greenhouse like my $50 hoop house.

These crops are almost completely freeze proof – especially spinach.  I’ve had temperatures down to 5 degrees with only minor damage to lettuce and none to spinach inside of a frost encrusted cold frame, and even less damage inside of the hoop house for some reason.  It’s easier to keep them growing in cold weather than to keep them from bolting (the elongation associated with going to seed which triggers instant bitterness) in early summer.

One of the beautiful things about cool weather gardening is the absence of insect and weed problems.  There are usually a few of both, but not to the point of being a problem.  Also having productive plants growing in January is really therapeutic to a gardener with cabin fever.

This picture was taken on Nov. 5 - with a little bit of effort (and a cold frame) your garden can be productive almost year around.

I’ve only mentioned cool weather plants in this post, but it’s worth mentioning that in my area most gardens go to the weeds by early August when they don’t have to.  If you want to have a 4 season harvest you have to plan and plant in all 4 seasons as well.  I’ve found that the late summer – early fall is probably the most challenging time because it is hot and dry, and insect pests are at their peak, and it just isn’t very much fun.  Nonetheless with just a little timely effort you can keep your garden productive by planting the right thing at the right time and also yanking out old plants once they stop being productive.

Doesn't that look delicious? Forcing rhubarb results in an earlier, tastier, more tender crop. The container used to force this rhubarb probably should have been taller - note that the tops are curled over. Sure is a pretty color though.

Rhubarb is a perenial plant which grows back from the root crowns every spring.  The large leaves contain high levels of oxalic acid and are poisonous, but the celery like stems are wonderfully tart and tangy.  Children like to eat them fresh right out of the garden, but nearly everyone likes it used as a fruit in sweet deserts – pies, crumbles, or just stewed with sugar.  My Mom (a marvelous cook of course – thanks Mom!) used to make it into a pie with strawberries.  My mouth is watering just thinking about it.  Don’t worry too much about those poisonous leaves – they apparently taste so nasty that there is not much danger of anyone eating them anyway.

Here in TN I can barely grow rhubarb – although last year was so cool and rainy that it did pretty well.  It really does much better farther north where the weather is normally cooler and wetter.  When I was a kid we lived in Indiana for a few years, and the back yard of the old house we lived in had a marvelous big bed of rhubarb that just took care of itself.

In good conditions rhubarb will pretty much take care of itself. They do like rich soil with lots of organic material and high fertility, and even moisture though.

Forcing rhubarb as in the first picture above is something that I had never heard of until recently, and I’ve never tried it yet – but I will.  Apparently forcing rhubarb is a widespread practice in England – I ran across it on a UK gardening blog that I subscribe to.  I’m afraid that the English are much more sophisticated gardeners on average than most Americans are – they seem to use many techniques that we don’t.  We should try to do better I suppose.

Anyway, from what I can glean forcing rhubarb is very simple to accomplish – as soon as growth is seen  (maybe even before)  cover the crown of a well established plant with a large, rather tall container such as a bucket or trash can.  Optionally insulate around the “forcer” with straw or some other mulch to warm the micro-climate and encourage growth.  In about 8 weeks you should have an early crop of tender juicy tangy rhubarb.

• Don’t try to do this until you have a well established healthy plant to work with – certainly not the first year!
• Don’t force the same plant two years in a row as the process stresses the plant by putting most of the energy into growing the forced stems instead of keeping the rest of the plant strong.

This simple trick will protect your tender seedlings from the intense sun, while still letting in plenty of light, and keeping out the bugs.

You probably already have some of these mesh flat trays - If you don't you can get them for cheap at most nurseries.

Just turn one upside down over your plants.

Then drape a peice of screen cloth over the top - you can buy screen by the foot at any home center.

You can weight down the edges of the screen cloth with boards or you can fold it under the flats.  You can also water right through the screen cloth.  You can even use this trick if you’ve direct seeded.  By the time your plants outgrow the inverted flats they will be big enough to survive the sun without the protection.

Try to pick an overcast day to remove the screen on if possible – otherwise do it in the afternoon when the sun has passed it’s highest intensity.  Remove the mesh tray a day or two later.