I did a lecture out at one of the local high schools today on growing Citrus in our area. For the most part, they were very attentive. There were a couple that really didn't seem that interested, but that's okay, it is high school after all.
The ones that seemed interested asked some very good questions. One in particular had to do with using a soiless medium in containers. Both the teacher and I thought this was an excellent question. Why do we use a soiless medium instead of good old garden soil?
Well, there a numerous reasons. To begin with, I don't care how good your soil is it will not provide adequate drainage, and over time it will become compacted. This will cause it to not have enough oxygen and interfere with the absorption of nutrients. Garden soil also tends to have clay in it which when dry resists water. When this happens the soil will tend to pull away from the sides of the pot, watering then becomes a real challenge as the water will just run down the sides and out the drainage holes.
There is also the hazard of introducing different non beneficial organisms. Potting mix that you buy in the bag has been sterilized to keep from introducing fungi, weeds, insects, nemetodes, etc.
So what exactly is a soiless potting mix?
The potting mixes you buy in a garden center are comprised of three basic ingredients: Peat moss, Pine bark, and either perlite or vermiculite.
Peat moss comes from the peat bogs of the northern United States and Canada. There are some peat bogs in the southern US, but the quality usually isn't as good.
Pine Bark comes from paper mills from all over and acts to provide moisture and fertilizer retention. It also gives a little more air space to the roots.
Perlite & Vermiculite are both volcanic in origin and are put into potting mix to provide additional air space. It is also used to lighten the mix up so it is not as dense and heavy. I have seen people use very small pieces of styrofoam to lighten it up and give more air space also.
One last piece of advice. Have you ever run out of potting soil in the middle of planting and had to improvise or go out and get some? Only to find out you have to get a different kind because they were out of what you were using?! I know I have. Make sure you mix the two different types or kinds of soil very well. You will have a better mix this way. If you just put one kind of potting mix on top of a completely different one and don’t mix them together there is the possibility that if the two mixes are different enough your plants will have a hard time growing down through one mix and into the other. The top mix might be heavier and compact the bottom soil for example. Thus, not allowing root penetration or air and water. It is kind of the same thing with planting in the ground. When you dig the hole, mix together at least part of the soil you took out with whatever you were wanting to add. If you don't, the roots may blow through the nice soft soil, then, when it gets to the garden soil they may start to curl around, like in a container. Basically creating a rootbound plant. Water can also sit in the bottom of the hole, like a tub.
I hope this has answered any questions about WHY you should use a potting mix instead of your garden soil. Your plants will thank you for reading this!
Happy Growing!
Darren
Showing posts with label Soiless Mix. Show all posts
Showing posts with label Soiless Mix. Show all posts
Wednesday, March 17, 2010
Saturday, March 13, 2010
A Deep Seeded Question
Well, just got home from the Carolina Yard Experience. It was a long day, but definitely a success. There was 572 people came through the gate for gardening and other yard information. I talked to many good folks, gave a couple of good lectures and demonstrated how to make permanent plant tags out of aluminum cans (see Tag Your It on this blog site).
I had one woman come up to me and ask about starting seeds. She had planted some 5 weeks ago and nothing came up. Also repeated the process two weeks ago with the same result. I was puzzled. Surely SOMETHING had to come up, even with very old seeds. She assured me they were fresh, she had just bought them. She was giving them warmth and good light. After about a dozen more questions, I finally found the answer. She was using a soiless potting mix, that was hydrophobic. It is basically afraid of water. She had planted the seeds and when she tried to water them, the water just sat on top. She then proceeded to just mist the plants every couple of days. The seeds never received any moisture to germinate. I got her straightened out and sent her on her way. I wondered how many other people have trouble with starting plants from seeds.
Here is the Readers Digest version.
Commercial seed-starting mixes, usually composed of vermiculite and peat, without any true soil, are recommended for starting seeds. They're sterile, lightweight and free from weed seeds, with a texture and porosity especially suited to the needs of germinating seeds and tiny seedlings.
You can use a flat, tray, pot, egg or cottage cheese carton or any other kind of container that has drainage. (Be sure to punch drainage holes in the cottage cheese cartons.) Make sure the containers are clean. Wood, plastic and clay pots can be brushed and cleansed with a solution of 10% bleach and 90% water, if they are moldy or slimy.
Set the cell flats or containers into a solid tray, fill them with potting mix, and water the mix before sowing seeds. The potting mix will settle down into the containers, sometimes dramatically so. Add more potting mix and water again, until the containers or cells are nearly full. Then sow the seeds according to the package directions.
Transplants grown indoors need adequate light. Under low light conditions, vegetable seedlings become leggy and weak and tend to topple over when they are a few inches tall. A total of 16 to 18 hours of light (natural and artificial) is required to produce stocky seedlings.
Containers can be placed near a south-facing window and receive supplemental light provided by fluorescent lights. Seedlings can be grown under fluorescent lights alone. Forty watt, 48-inch long fluorescent tubes, with a timer, placed 2 to 4 inches above the seedlings is an adequate set-up. Consider attaching aluminum foil from the light fixture to reflect light onto the plants.
Seedlings growing in soiless mixes need to be fertilized when the first true leaves appear. Feed at every other watering with a water-soluble starter fertilizer to promote faster plant growth and until the plants are ready to plant outdoors. Wash the seedlings with plain water to remove any fertilizer from the leaves. Water between feedings with plain water to prevent any salt from accumulating in the media. Seedlings growing in mixes containing compost, rotted manure or commercially prepared soil may not need to be fertilized.
Water the transplants when they are slightly wilting. Stop watering when water runs out of the bottom of the container. For soilless media, determine the need for watering by squeezing the top half-inch of media between the thumb and forefinger. If water squeezes out easily, there is adequate moisture; if the medium feels slightly moist but water is difficult to squeeze out, water should be added.
Before the transplants are moved into the garden, they need to be hardened off. To condition plants to growing outdoors, set the seedlings outdoors during the day and bring them inside before sundown. The plants should be gradually exposed to more direct sun to avoid injuring the plants. Outside, the seedlings are exposed to varying temperatures, more direct sunlight, drying winds and greater moisture stress. The transplants will produce a cuticle on leaf and stem surfaces to reduce water loss. Continue this routine for two to three weeks to condition the seedlings. This adjustment may result in a temporary slow-down of growth, but it helps the plant successfully adapt to outdoor conditions. The adjustment must be gradual or the plant will be damaged, resulting in delayed growth, retarded fruiting and reduced yields when the plants are set out. Before being planted in the garden, transplants can also be moved to a hotbed, coldframe or other outdoor location where there will be plenty of sunshine, adequate ventilation and suitable temperature.
I hope this answers any questions or solves any problems you may have. Buying seeds is so much cheaper and there is a MUCH larger selection of varieties out there. Check online or your favorite garden catalog and try something new this year! The box stores can carry just so many plants and most of the time it is just the basics.
Happy Growing!
Darren
I had one woman come up to me and ask about starting seeds. She had planted some 5 weeks ago and nothing came up. Also repeated the process two weeks ago with the same result. I was puzzled. Surely SOMETHING had to come up, even with very old seeds. She assured me they were fresh, she had just bought them. She was giving them warmth and good light. After about a dozen more questions, I finally found the answer. She was using a soiless potting mix, that was hydrophobic. It is basically afraid of water. She had planted the seeds and when she tried to water them, the water just sat on top. She then proceeded to just mist the plants every couple of days. The seeds never received any moisture to germinate. I got her straightened out and sent her on her way. I wondered how many other people have trouble with starting plants from seeds.
Here is the Readers Digest version.
Commercial seed-starting mixes, usually composed of vermiculite and peat, without any true soil, are recommended for starting seeds. They're sterile, lightweight and free from weed seeds, with a texture and porosity especially suited to the needs of germinating seeds and tiny seedlings.
You can use a flat, tray, pot, egg or cottage cheese carton or any other kind of container that has drainage. (Be sure to punch drainage holes in the cottage cheese cartons.) Make sure the containers are clean. Wood, plastic and clay pots can be brushed and cleansed with a solution of 10% bleach and 90% water, if they are moldy or slimy.
Set the cell flats or containers into a solid tray, fill them with potting mix, and water the mix before sowing seeds. The potting mix will settle down into the containers, sometimes dramatically so. Add more potting mix and water again, until the containers or cells are nearly full. Then sow the seeds according to the package directions.
Transplants grown indoors need adequate light. Under low light conditions, vegetable seedlings become leggy and weak and tend to topple over when they are a few inches tall. A total of 16 to 18 hours of light (natural and artificial) is required to produce stocky seedlings.
Containers can be placed near a south-facing window and receive supplemental light provided by fluorescent lights. Seedlings can be grown under fluorescent lights alone. Forty watt, 48-inch long fluorescent tubes, with a timer, placed 2 to 4 inches above the seedlings is an adequate set-up. Consider attaching aluminum foil from the light fixture to reflect light onto the plants.
Seedlings growing in soiless mixes need to be fertilized when the first true leaves appear. Feed at every other watering with a water-soluble starter fertilizer to promote faster plant growth and until the plants are ready to plant outdoors. Wash the seedlings with plain water to remove any fertilizer from the leaves. Water between feedings with plain water to prevent any salt from accumulating in the media. Seedlings growing in mixes containing compost, rotted manure or commercially prepared soil may not need to be fertilized.
Water the transplants when they are slightly wilting. Stop watering when water runs out of the bottom of the container. For soilless media, determine the need for watering by squeezing the top half-inch of media between the thumb and forefinger. If water squeezes out easily, there is adequate moisture; if the medium feels slightly moist but water is difficult to squeeze out, water should be added.
Before the transplants are moved into the garden, they need to be hardened off. To condition plants to growing outdoors, set the seedlings outdoors during the day and bring them inside before sundown. The plants should be gradually exposed to more direct sun to avoid injuring the plants. Outside, the seedlings are exposed to varying temperatures, more direct sunlight, drying winds and greater moisture stress. The transplants will produce a cuticle on leaf and stem surfaces to reduce water loss. Continue this routine for two to three weeks to condition the seedlings. This adjustment may result in a temporary slow-down of growth, but it helps the plant successfully adapt to outdoor conditions. The adjustment must be gradual or the plant will be damaged, resulting in delayed growth, retarded fruiting and reduced yields when the plants are set out. Before being planted in the garden, transplants can also be moved to a hotbed, coldframe or other outdoor location where there will be plenty of sunshine, adequate ventilation and suitable temperature.
I hope this answers any questions or solves any problems you may have. Buying seeds is so much cheaper and there is a MUCH larger selection of varieties out there. Check online or your favorite garden catalog and try something new this year! The box stores can carry just so many plants and most of the time it is just the basics.
Happy Growing!
Darren
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