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I’ve gotten quite a few questions on what to do with these plants that are sprouting up all over people’s kitchens and living rooms! Some of the specific topics we’re going to cover today are:

• Algae on Growth Medium – that green stuff growing on your seedling growing medium
• How Much Light Should My Seedlings Get – what levels of light do your plants need going forward, concerns and problems, how to prevent problems before they get started, and tips for getting the most out of your lights.
• Air Movement – Symptoms of not enough air movement, too much air movement, and a simple method for fixing the problems
• Thinning Seedlings – When and how, and how to cheat
• Insect Pests – Aphids are your most common pest at this phase of indoor cultivation, how to deal with them.
• Watering Seedlings – How to tell if you are over or under watering
• Fertilizing Seedlings – When to fertilize and what to look out for with deficiencies

Algae on Growth Medium

Some of you might see green stuff growing on the surface of your seedling soil, it’s algae! This stuff grows more commonly in soilless mixes with peat moss in them, it is generally harmless but often indicates you are over watering. So if the seedling is up and growing and you start to see green algae growing, you probably need to cut back on watering, it’s also caused by too much humidity, so some airflow would help reduce it’s incidence but again it’s not a huge problem. It’s best to let it dry out a little and then disturb the soil surface just slightly with something like a table fork, just scratch the soil surface to break it up. It can make problems for you if it is allowed to continue cause it’ll make an almost airtight barrier and cause your soil to go anaerobic and kill your plant. So just let it dry out a little, scratch the soil surface, water from the bottom, and maybe water a little less too.

How Much Light Should My Seedlings Get?

I have grow lights, and most people are going to be using grow lights or keeping seedlings in a southern window, so I’ll mostly talk about grow lights cause that’s the only real thing we can control! You will want to keep your grow lights a sufficient distance away from the seedlings that they aren’t burned, about a foot to 18 inches for more powerful T-5 flourescent fixtures, as little as 3 inches for lower power T-8 or T-12 flourescent fixtures. If you’re going with LEDs, look up recommended distances cause I’ve never used them. You want to set an automatic timer to keep the lights on for 15 or 16 hours. Doesn’t matter if the seeds haven’t all germinated, or if they are 6 inches tall. Just watch the taller plants and make sure they don’t get close enough to your lights to get burned, look up sun scald pictures on the internet, or leaf scald to see what it looks like. If the plants seem to be growing spindly, they need more light, so lower your lights. I purposefully let my tomatoes get a little spindly so they are easier for me to plant the way I like to plant tomatoes. If you’re interested in my not-so-super-secret tomato planting method, you should check out episode 2 where I talk about it in detail.

Here’s a tip for getting a little more out of your lights, the better the reflector, the more light will hit your plants, you can also get mylar backed insulation board at home improvement stores, cut it to fit around your growing area and use it to reflect light back onto your seedlings from the sides where the light would otherwise not be used. If you are in a window, put that mylar board behind the seedlings and to the sides to reflect as much of your sunlight as possible, it can sometimes help with keeping the seedlings growing straight depending on how you position the reflected light. You should also put your fastest growing and most light hungry plants front and center under your light fixtures and put the cooler temperature loving plants to the outside edges.

Air Movement

You can tell you have too little air circulation when you have algae problems, fungal diseases, and other problems like that. You can set up one of those tiny ocillating fans to blow air indirectly on your seedlings to really strengthen them and keep a much healthier environment for them. It reduces humidity which helps reduce disease problems, and causes them to grow with a stronger stalk which helps them later on when they are transplanted outside in the natural world with wind and rain to push them around.

Thinning Seedlings

If you have two or more seedlings growing in each cell of your flat, you probably should thin them out to leave the strongest seedling. Most of those cells are too small to raise multiples, and you will have reduced yields if multiple plants are competing for the same space, water and nutrients in the garden later on in the year, so go in there with some small scissors and snip off the weaklings and put them in the compost pile. Some people get all weepy eyed at the idea of killing little plants, but you will regret it if you don’t thin your seedlings! If you are careful, and catch them early, you can prick out which means to transplant gently, the duplicate plant and transfer it to an empty cell. But be careful, if you crush the stem, it will die, and if you damage the remaining plant’s root system enough, you could kill it too, so understand it might be a gamble. I sometimes do it, but never with rare or expensive plants.

Insect Pests

Aphids are going to be your biggest problem bugs. They suck the juices out of your seedling plants and weaken them to the point of dying if not controlled. If you’re growing indoors, it’s almost a sure thing that you’re going to have aphid problems. So you can go buy some insecticidal soap or you can make your own. If you are listening to this and they’re already at horrific levels, go buy it and use it, then experiment with your homemade version later. For the homemade sprays you can go with straight up insecticidal soap by mixing

2 teaspoons of soap per quart of water – I like to use a natural soap because it has certain properties that actually dissolve the aphid’s outer shell and dehydrate the evil little creatures to death

I love garlic for preventing damping off and other early stage disease problems, and once again we’ve got garlic to the rescue!!

To make a garlic oil spray, finely chop or pulverize a whole head of garlic, and add that to about 4 teaspoons of mineral oil. Let this mixture sit for about 24 hours. Then I like to pour it through a rag from an old tshirt to strain out the garlic pieces cause then I can squeeze it to get everything out. Or if you have a fine metal strainer, you can use that and press the garlic cloves with a spoon. You then combine the strained garlic oil with a pint of water and one teaspoon of liquid dish soap or liquid castile soap again I prefer the castile soap.

You can store this mixture and dilute it as needed. When you need to spray, just use one ounce (2 tablespoons) per pint of water in a sprayer.

To use this kind of garlic oil spray, first test it on each of your types of plants by spraying a couple leaves or just a couple whole plants to see if your mixture causes any harm. Some plants are more sensitive than others, you should take the same precautions with the insecticidal soap spray by the way. If there’s no signs of yellowing or other leaf damage after a day or two, it should be safe to use. If there is leaf damage, you should dilute the mixture with more water and try it again. Once you dial in the right concentration, spray the whole flat, and make sure you pay special attention to the undersides of the leaves cause that’s where the little buggers like to hang out.  Be careful because this is a non-selective insecticide, which means that it will kill beneficial insects just like it kills the bad ones.

Watering Seedlings

Now we’ve already touched on this a couple times but I wanted to bring up some specifics. If you can, you should be bottom watering. That means you fill the tray the seedlings are in with water and let them soak for 5 to ten minutes to soak up water from the bottom, then you either drain off the water, or remove the cells to a dry tray and soak the next batch. If you do it like this, you will have fewer disease problems, and you will actually spend less time watering cause you will give each cell a good soaking that will last longer than if you water from the top. In most situations, you will probably only need to water like this once or twice a week, maybe fewer. But pay attention, it’s almost always better to let the plants get a tiny bit wilted than to overwater them. Most people overwater, don’t be most people!

Last but not least…

Fertilizing Seedlings

You do not have to worry about fertilizing your seedlings until they start to show their first set of true leaves. The first set of leaves to come out of the seed are called the cotyledons, they are the seedling leaves, the next set of leaves to grow are called true leaves and almost always look very different than the cotyledons. As soon as you see those true leaves coming out, you should start fertilizing those little plants. Go easy on them they don’t need much and too much can kill them. Less is more in most situations. I recommend one of the following methods of feeding.

If you are brand new to gardening, just follow the directions on something like miracle gro seedling fertilizer. I know it’s awful stuff but it works, and I’d rather see you use that and have a successful garden this year than screw things up with some fancy method that is over your experience level. With that said, here are 3 better ways that are relatively hard to mess up.

• Neptune’s Harvest Organic Hydrolyzed fish fertilizer Use ½ oz of (1 tablespoon) per gallon of water, once a week. You can reduce that to a quarter of an ounce per gallon of water and use that every time you water which will probably only be twice a week. Once the first true leaves are out, and the plants are 4 to 6 inches tall, increase the concentration to 1 oz. per gallon of water, once a week.
• 1 oz Mittleider weekly feed in 3 gallons of water for every watering
• Mix 1 cup of worm castings in 1 gallon of water. Let it soak until the water turns to a medium brown color which normally takes about 24 hours. You can use that worm casting tea to fertilize your seedlings once a week. And shake it up so any solids that settled to the bottom are applied along with the tea.

If you suspect your seedlings are deficient in something here are some warning signs. I’ll have this list posted on the website if you want to print it off or refer back to it at a later date.

That pretty much wraps things up guys, I hope you enjoyed today’s show, share the episode or the Facebook group with your gardener friends and if you really want to help out, please go to iTunes and leave an excellent review, it helps me to grow the show!  I hope you have a wonderful day, and as always “Go Do Good Things”