You don’t have to use loose potting soil to grow your seeds or cuttings. There are many options for preformed plugs, both natural and synthetic, that can make propagation easy and tidy, while providing a good environment for your cuttings and seeds.

Dry compressed coir pellet plugs in a watertight seed-starting tray.
PC: Leslie F. Halleck

Compressed soilless plug pellets, also known as seed plugs, are one easy option. These are compressed dry disks of peat or coir, plus a small amount of fertilizer, wrapped in a biodegradable film. Often, seed plugs are sold with small seed-germinating greenhouse kits or you can buy them separately.

This arugula is ready to transplant.
PC: Leslie F. Halleck

When using seed plugs, it's easy to see when you should transplant your plant to a larger size. Once roots reach the edges of the plug, it's ready to go into a larger pot or even straight to outside!

Chemical inhibitors prevent the seed from germinating under the wrong environmental conditions. Otherwise, seeds would germinate at the wrong time, out of season, or in the wrong location and die. Inhibitors also make it possible for seeds to travel some distance away from the parent plant, which helps plant species spread geographically and improve genetic diversity.

Sometimes, chemical germination inhibitors break down and a seed will germinate too early. Have you ever seen a seed sprout inside a tomato fruit?

The germination inhibitors inside this decaying tomato have broken down and the seeds inside have begun to germinate. By the way, don’t eat those tiny tomato sprouts if you find them in your tomato fruit—tomatoes are in the nightshade family and the stems and leaves contain toxins.
PC: Leslie F. Halleck

This type of germination is called precocious germination, or vivipary. It happens when the hormones that regulate seed development & degrade, causing seeds to germinate- even under the wrong environmental conditions.

PC: Leslie F. Halleck

For most annual and edible seeds, normal germination occurs at optimal soil temperature and moisture levels without any special techniques. But you can speed up the germination process (or improve germination rates from older seed stock) if you pre-sprout them, a process called chitting or greensprouting. Chitting involves soaking the seeds, usually for 24 hours (some species require more time), before you sow them into pots or into the garden.

As these seeds soak up water during chitting, they swell, and the germination process begins.
PC: Botanopia.com

How to Chit Seeds

• Moisten some dish towels, paper towels, or newspaper to the dampness of a wrung-out sponge, then set the damp material in a tray or on a plate.
• For seeds that sprout quickly, such as beans (1-3 days), simply spread your seed onto the moist surface. For seeds that take longer & need more constant moisture or harder seeds that take longer to sprout, like succulents and cactus, insert the moistened dish towel or paper towel into a small plastic baggy, place seeds inside, and seal the baggy.
• Place in a warm spot in your home.
• Seeds will absorb the moisture & swell, some will germinate & being to sprout. Immediately plant these sprouted seeds into a water rooter, growing media or seed plugs.
• If your seeds have been molding, then dilute a 1:25 ratio of hydrogen peroxide to water & wipe the seeds with the solution before you place them into the moist towel.

Citrus seeds benefit from pre-sprouting, and will then root more easily..
PC: Leslie F. Halleck

Seedlings Need Bright Light

Once a seedling emerges from beneath the soil, both the amount of bright light and the duration of light are important. Seedlings need 14-16 hours of bright light to grow strong & study. If you notice your seedlings are elongating & stretching, they are not receiving enough light.

Look for HO T5 fluorescents when you’re shopping for growing lamps; skip the standard shop lights.
PC: Leslie F. Halleck

When I am growing seedlings, I use HO T5 fluorescent of LED fixtures that hold up to four lamps. These setups will provide the intense light that young seedlings need. The goal is to deliver even amounts of light to the entire seed tray - even the edges.

One of my grow shelves.
PC: Leslie F. Halleck

My Seedling Grow Light Set-up

I like to create grow shelves for my seedlings and cuttings with an adjustable shelving unit. I make shelves different heights for different sized plants, so I can move them around as they grow. I use large 4-foot fluorescent light fixtures (which can hold both HO T5 fluorescent and T5 LEDs) on these shelves in my garage, where there is no ambient light available.

If you have wire shelving in your garage, be sure to purchase plastic shelf covers so they will contain any water drainage.

Some seedlings can be planted deeper in the soil than they were growing. Look below. Can you see the fuzzy part of the tomato stem that has a purple tint? You can bury that portion of tomato stem under the soil, as it will develop new adventitious bracing roots from that part of the stem.

So, if you accidentally waited too long to transplant, or your seedlings stretched due to lack of light, you can get your seedling back on track by planting a little deeper.

Once I've checked the root system of my tomato plug & found it large enough for bumping up I filled a 4" pot with loose potting mix, then used a dibber to make a plug-sized hole for the tomato seedling. I dropped it into the hole & then gently pressed soil about the root ball & covered any exposed root area with some additional potting mix.

If you sniped this seedling off right at the soil line, you could also use it as a stem-tip cutting—the stem will grow new roots from the purple area.

Plant Parenting Book

Maintaining proper moisture is key to successful germination and healthy seedlings. The growing media should always be damp to the touch, like a wrung-out sponge. Never let it dry out, but don't let it stay too soggy either.

A new seeding of peas topped with coir.
PC: Leslie F. Halleck

One trick to maintaining even moisture as seeds germinate and keep the surface of the soil from drying out is to sprinkle a thin layer of a material such as coir or vermiculite on top of the soil. I prefer to use coir. These materials will hold additional moisture, which can help prevent your seeds from drying out before they germinate.

Coir after it has been rehydrated.
PC: Leslie F. Halleck

Coir is a lightweight material made from the byproduct of coconut husks. It absorbs and holds water, while aerating the soil. Coir typically comes in a compressed block that you soak in water to rehydrate. After it soaks up water, coir becomes light and fluffy.

Once your seeds have germinated, it is time to thin their numbers. This part can be tough—no one wants to kill the seedlings they just grew.

When too many seeds germinate too closely together, the seedlings can struggle. It is tempting to let them all continue to grow, but your seedlings will be better off if you cull the weakest ones. More than one seedling per cell causes too much shading and resource competition, resulting in weaker seedlings overall.

If multiple seeds germinate in the same cell, keep the strongest and snip off the extras.
PC: Leslie F. Halleck

After your seeds have sprouted, choose the strongest, stockiest seedling in each cell and snip the remaining seedlings at the base. Throw the excess seedlings on your salad or feed them to any critters that would appreciate some greens.

When it comes to plant cloning, you'll probably take more stem cuttings than any other type. Herbs are a fantastic place to start multiplying your outdoor garden this spring as they are easy and quick to root by stem-tip cuttings.

Tip cuttings of oregano, watercress, lavender, thyme, rosemary, and a different variety of oregano.
PC: Leslie F. Halleck

Above, I used small short snips to remove a 2-inch section that contains two or three nodes along the stem. Each of these herbs will typically root directly in water, if I choose not to root them in a growing media. Make sure to remove any leaves that will be below the water or soil line.

I used a porcelain sprouting plate to keep cuttings from falling into water.
PC: Leslie F. Halleck

Don't overcrowd your cuttings. While you must maintain humidity around the cuttings during rooting, they also need good air circulation. Rooting media should be kept moist, but not soggy.

Herb stem-tip cuttings stuck in rockwool.
PC: Leslie F. Halleck

Herb tip cuttings can also be rooted in a lightweight growing media. Dip cutting in rooting hormone before sticking them. And be patient: while most herbs root relatively quickly, you will find that different plants will require more time than others.