You know that you have farmer friends when they want to start transplants for their birthday. My friend Labria had a birthday earlier this month. When we talked about how to celebrate, she said “It’s nice outside, let’s start our transplants”.
You see, in Michigan early March usually consists of a lot of cold, some snow, and a lot of rain. This day was sunny and relatively warm. We started about 30 flats of plants for both of our farms and I got the idea for this post. Happy Birthday Labria and happy planting to all of you!
How to Start Vegetable Transplants at Home
Before you just shove some seeds in the dirt and hope for the best, let’s discuss what you need to do first. Keep in mind, this is my opinion and experience. It is not the only way to do things. This is just what I do.
1. Plan your garden before you order seeds
It’s easy to get carried away in December when all those glorious seed catalogs start coming in the mail. You see the pictures of giant watermelons, juicy tomatoes, perfect ears of corn, and beautiful straight carrots in every color imaginable. If you don’t plan, you can easily spend a ton of cash on seeds that will not be used this year.
What I like to do is get a sheet of graph paper and draw to scale each garden area I want to plant. I design my sketch so that one square on the graph represents 6 inches of planting space. Then, I make a list of all the crops and varieties I want to grow.
Next, I lay out their spacing on the graph paper so I know exactly how many plants/seeds I have room for. Now, I have a realistic idea of what I need to order.
2. Order seeds
Not all seed catalogs are created equal. Most vegetable varieties are purchased by the packet. For some companies, a packet of tomato seeds includes 25 seeds. For others, a packet is 10 seeds. When you are looking through catalogs, pay attention not just to the price but to the number of seeds you’re getting. Two of my favorite seed companies to work with are Johnny’s Selected Seeds and Baker Creek Heirloom Seeds. They are employee owned companies that provide a wealth of information about the seeds that you buy. Their germination rates are above average and their genetics are reliable. You may have your own favorites, leave a comment and tell us about them.
3. Gather supplies and build your shelves
While you’re waiting for your order to process and ship you should be thinking about what you’re going to put the seeds in, and where you’re going to grow them. You can start a seed in almost anything. Some people use eggshells, egg cartons, dixie cups, newspaper pots, peat pellets, soil blocks, or the more common plastic cell trays. Each have their pros and cons.
I have reusable hard plastic cell trays. I bought them probably 10 years ago and have used them at least twice a year since then. The thin cell packs you get at the greenhouse may be a little cheaper to buy up front, but you’ll be lucky if they last 2 years let alone 10 or more. I feel less guilty about using plastic if the product will last for a long time before it is recycled.
Here are some links to the trays I use.
- Used for tomatoes, peppers, eggplants, cucumbers, melons, squash, or any plant that will be large upon transplanting.
- Used for brassicas like kale, collards, or broccoli.
- Also used for flowers or any small seed that will later be re-potted into a larger container
- Put these under your cell pack inserts to catch water runoff
- Use to start onions, grow microgreens or wheatgrass
Now that your seeds and trays are on their way, you need somewhere to grow these plants. A window sill is not sufficient. Growing healthy transplants indoors requires supplemental light. I didn’t want to spend a bunch of money on high pressure sodium or metal halide grow lights. Instead, I built a cheap shelving unit in my basement and used a little farmer ingenuity to make it work.
This is the heavy duty Metal shelf I started with. I picked this one because it was 24 inches deep and 48 inches wide on each shelf. This allowed me to place 4 cell trays on each shelf without an overhang. The first time I built one of these I built, I used the $30 plastic shelf from home depot. It worked, but the lights and cell trays would overhang the shelves. This became annoying the next year when I wanted to wrap the shelf in mylar to reflect more light and hold in heat.
I had picked up a few florescent tube shop lights from a yard sale and that is what I used. By all means, if you can afford it, buy the awesome LED grow lights. Each shop light is 48 inches long and hold 2 bulbs. In order to get the full spectrum of visible light (which plants require) you need to buy one “cool white” bulb and one “warm light” bulb for each fixture. The cool bulbs provide the violet/blue/green end of the spectrum and the warm bulbs provide the yellow/orange/red (and you thought ROY G BIV wouldn’t come in handy). After fitting each fixture with one of each bulb, attach 2 fixtures per shelf on the shelving unit. I did this with the little chain and S hooks that came with my shop lights. You can also use zip ties, nuts and bolts, or those cool pulleys that allow you to raise and lower the lights.
When your plants are short you want them 3-6 inches away from the lights. I have found that it’s easy enough to just place an empty flat upside down under each tray when my plants are small and remove them when they get too close to the light fixtures. You do what works for you.
4. Transplant timing
I assume that most of you know when your last frost date is for your area; or when it is safe to plant warm season transplants outside. If not, let me know and I’ll do a blog post about that later. Knowing when you want to plant outside is key to knowing when you should start your transplants. Every seed takes a certain amount of time to germinate. This is useful information to know beforehand. One reason I love Johnny’s seeds is because they provide the optimum temperature and approximate time for germination of each seed in their catalog description. For the sake of time, I’ll use tomatoes, cucumbers and bell peppers as an example.
I like an 8 week old transplant for tomatoes, and a 10 week old transplant for peppers. At this age the plants are old enough to stand up to the wind and rain, but not so old that they become root bound inside a 50 cell tray. The peppers are allowed an extra 2 weeks because their seeds take longer to germinate, and they grow a little slower than the tomatoes.
Cucumbers (or any other member of its family that grows a vine) are a different story. Their seeds germinate relatively fast, their leaves are larger, and they grow quickly. I will usually start my cucumbers about 4 weeks before planting outside. Sometimes, if I am short on space in my shelf, I will just direct seed them outside.
If I just split the difference and started all 3 of these crops 8 weeks before planting the tomatoes would be fine, the peppers would be a bit small, and the cucumbers would more than likely require their own shelf because the vines would grow large and unruly.
5. Mix your dirt
Finally! Everything is in place and you are ready to get into the dirt! When using small cells to start your plants you want a light and fluffy soil that retains moisture, but still has enough nutrients to feed your plants for the 4-10 weeks they will be in their tiny homes.
My favorite transplant soil is from a Michigan company named Morgan composting. I use 2 of their products, 101 for 72 cell flats and 201 for 50 cell flats. If you do not live in this area you can use any regular potting soil from a big box store and mix it with a little more vermiculite and perlite.
I dump all of my soil and amendments into a storage tote and add water until the soil will form a ball when squeezed, but not drip water off of your hand.
Mix it well and load up each cell in your flat. Poke each cell to make sure they have an even amount of soil in each hole.
6. Plant seeds
Each seed likes a different planting depth. Consult your seed pack or the catalog for recommendations. A good rule of thumb is about 1/4 inch to 1/2 inch for most seeds. I use the end of a sharpie to poke holes in each cell of the flat.
Drop in your seeds and dust your hand over the flat to cover them with soil. I use Popsicle sticks or small wooden plant markers to label each flat with the variety name, days to maturity, and the date they were planted. This will save you a lot of heartache later on when you are planting in your garden.
7. Adjust timer and lights
Each one of my shop lights has its own power cord. I use a surge protector and zip ties to run all the wires over the top of my shelf and to the electrical outlet on the other side. I plug the surge protector into a timer that will automatically turn the whole shelf on and off at a set interval. During germination I leave the lights on 24 hours a day to keep everything warm (my shelf is in a basement). Once the seeds have popped, I change the timer to about 16 hours of light and 8 hours of darkness and let them do their thing.
8. Wait, watch, water, thin
Check on your seeds regularly to make sure they have enough water and haven’t grown to touch the lights. If you were a little heavy handed with seeding you may need to thin. I used some 5 year old seed to plant this tray of collards. I was afraid the germination rate would be low due to the age of the seed so I put multiple seeds in each cell. About a week later I found myself thinning the whole tray because each cell had 4-5 plants!
Hopefully this has been helpful to you. If so, hit the subscribe button on your right to receive a notification when I post new stuff. Happy Spring!