To answer the question of how long it takes plants to grow, the answer is dependent on their size. To determine if your plants are suitable for planting, look to see if they have developed a set of genuine leaves. A common blunder made by gardeners is assuming that the seedlings already have their real leaves, while in fact they just have seed leaves.
The Minnesota State Horticultural Society stresses the need of waiting until seedlings have established true leaves before transplanting them. How long your plants will remain in trays is based on the same principles as this. You can also start your plants in the greenhouse to avoid transplant shock and downsides, so that they’ll grow strong for transplanting.
WHAT PROPAGATION TRAY IS BEST FOR YOU?
Several variables must be taken into consideration when determining the ideal size of your cell plug seed trays. Our goal is to provide you with as many options as possible so that you may make an informed decision. Consider the purpose of your seed starting first.
WHAT SIZE CELL TRAY SHOULD I USE?
Go over the seed starting questions again quickly.
- In order to transplant row crops, are you producing a huge number or one variety of plants?
- Are you planting a wide array of plants in lower numbers?
- You can use the succession planting strategy, or you can plant your crops all at once.
- Specify the seed type you intend to use. What about peppers, tomatoes, lettuce, watermelon, etc.??
- What is the size of the seed?
- Do your seedlings need to be kept in the cell trays for an extended period of time?
- Planting right from the plug trays is an option, or will you be potting up your seedlings first?
- To begin, how much seed starting area do you have available?
- For germination will you utilize a heat mat, or will you simply use the ambient temperature?
WHAT SIZE CELL SEED TRAYS SHOULD I USE?
THE BEST PLUG TRAYS FOR HOME GARDENS.
Seed Starting Trays with 32 cells
The 32 cell plug propagation tray inserts from Bootstrap Farmer measure 2′′ x 2′′ and are the largest cell seed beginning tray size available. They are ideal for crop canopy development because of their bigger size.
Inserts for cell seed trays can be utilized in two different ways. Plant directly into the cell inserts with deep drainage holes using Rockwool cubes, soilless media, or soil mediums. Using a 1020 shallow tray with no perforations, the entire tray can be bottom-watered.
This seed-starting pot holder is another usage for the insert tray. The insert holds 32 of these 2.5-inch pots securely in place in a 1020 shallow tray with no holes, making it easy to move them to the garden space after planting. It is highly common for school and community projects to use the individual seed cup design since it may be used directly from seed to transplant without the need for additional potting.
Trays of 50 seed starter cells
Using these 50 cell propagation trays, you may save room in your seed starting environment while still planting huge numbers of lettuce seedlings that will be directly transferred. Using a 50 cell tray instead of 72 cell plug trays or 128 cell trays will allow you to have more room for root growth during transplanting. These trays will save your plants from becoming root-bound if the weather is uncooperative in the Spring. This size also allows the seedling to build a canopy.
Select one of the cell trays listed below, or plan on potting up into larger pots like our new 5 inch grow pots with carrier if you know your seedlings will need to be potted up before they are ready to move outside.
Planting early greens like broccoli and collard greens in plastic trays of this size is ideal for the home garden. It’s a good idea to make sure that the germination and transplanting times of all the kinds in a single cell tray are the same.
THE BEST CELL PLUG TRAY SIZE FOR LARGE SCALE MARKET GARDENS
Seedling Trays with 72 Cell Plugs
One of the most popular options for market gardeners is the 72 Cell tray. As far as growing space and seedling density go, these are a good compromise. A wide range of plants can thrive in the 1.5″ square and 2.25″ deep cells. Vine plants can also benefit from the use of these plastic trays. To avoid root bound seedlings, you’ll need to transplant the vine plants earlier than you would with the 32 Cell trays. Use a heavy-duty 1020 deep tray with this cell plug tray for bottom watering.
TRAYS OF 128 CELLS
Row crops or a large number of baby greens can be successfully started in these 128 Cell Trays. This set-up is great for germinating a large number of seeds, but it’s not designed for long-term cultivation. Cells each have a diameter of 1 inch and a depth of 2.25 inches. Compared to the more popular 72 cell seed starter trays, you may plant 78% more seedlings each tray. The heavy-duty 1020 deep tray for bottom watering is compatible with these 128 seed trays. Seedlings should be moved from this seed tray to a larger pot or grow bag if they are not going to be transplanted outside for an extended period.
TRAYS OF 200 CELLS
You can save money by growing small-seeded crops like lettuce and cole vegetables in these 200 Cell Trays. With a single tray, you can grow up to 2.8 times as many plants as you could in a 72 cell tray. Each cell is 0.75′′ square and 2.25′′ deep. ”
If you’re starting seeds in a 200-cell plastic tray, you’ll need to transplant your seedlings earlier in their development. Once they have one or two sets of genuine leaves, they are typically done. Large-scale farmers and gardeners who want to pot up their seedlings several times before transplanting them to the garden usually use this plastic tray size. If you use a soilless media like coco coir or ProMix, they can also be utilized to start plants in hydroponic systems.
COMMON QUESTIONS ABOUT PLANTING IN CELL TRAYS
CAN I PLANT ROOT CROPS IN PLUG TRAYS?
If your environment does not allow for direct sowing of root crops like beets and turnips, cell seed trays may be an option. However, it is not recommended. It is the taproot of these vegetables that provides the bulk of their nutritional value. If the plant’s long core root is broken or disrupted during the transplanting process, it will not be able to grow properly.
CAN ONIONS AND LEEKS BE PLANTED IN SEED STARTING TRAYS?
Yes, alliums have clustered root structures, unlike other root crops. As a result, these plants are far more tolerant to root disruptions during transplantation. It is typical practice for growers to put numerous little seeds in a cell and then separate them for transplantation later.
WHAT ARE THE ADVANTAGES TO STARTING SEEDS IN CELL TRAYS VS. LARGER POTS?
The ability to start more seedlings in a grower’s growing space is one advantage of starting seeds in cell trays, especially the larger ones. It’s especially useful for row crops, where a farmer would wish to sow 100 or more varieties of each one. This many seedling starts would take up an absurd amount of room if they were grown in larger seed pots. You’ll also save on growth media because you won’t have to sow your seeds in fresh pots and then transplant the sprouted plants into larger ones.
CAN YOU OVERWATER SEEDLINGS IN CELL SEED TRAYS?
Yes. Overwatering seedlings grown in cell trays is conceivable. Inexperienced growers often make the error of constantly filling the bottom 1020 tray with water. Your seedling will no longer be able to obtain oxygen as a result of this. In order to correctly water the bottom of a 1020, only provide enough water to allow the cell tray to absorb it evenly when watering. If you don’t get rid of the surplus water, anaerobic bacteria will be attracted to your seedlings and wreak havoc.
HOW LONG CAN MY PLANTS STAY IN THE CELL TRAY?
Seedlings can be kept in cell trays for up to four weeks, depending on the variety. A plant’s ability to grow before becoming root-bound is directly proportional to the volume of its cells. A 200 cell tray plant will likely need to be potted up or moved outside after it has a complete set of true leaves. Six to eight weeks in a 32-cell insert pot is enough time to produce plants.
WHY ARE MY TRANSPLANTS NOT GROWING?
Your seedlings may become root-bound if they’ve been in the plug tray for too long. When you remove the plug from the tray, you will notice a significant number of roots surrounding it. Root-bound plants are less able to grow new roots and are more likely to remain stunted.
If your garden plants are suffering from transplant shock, they may grow too small all season. Check out our Seed Starting 101 Guide for more information on transplant shock and how to harden off your transplants.
CAN I FIX A ROOT-BOUND SEEDLING OR PLANT?
Planting time can be shortened if your seedlings become root-bound before you can get them in the ground. Remove plug from cell tray and gently tap bottom of roots to release soil. Tease apart roots with fingers once loose soil has been taken from them. Tearing a few roots along the way is perfectly acceptable and even encouraged. Root looping can be prevented by tearing and separating the roots, which will encourage the transplant to grow new side roots.
WHEN TO TRANSPLANT SEEDLINGS OUTSIDE
The task of transplanting sensitive seedlings to the outdoors of a farm or garden is a regional one. Seasonally appropriate plants can be transplanted year-round in Zones 8-11. Colder climates may necessitate a single late-Spring transplant of seedlings once nighttime temperatures rise to at least 50°F. In a hoop house or cold frame, you may be able to move up your planting date by several weeks.
Any seedling, whether acquired from a local nursery or started yourself in seed starting trays, should be transplanted once it has reached the appropriate stage of growth and the outside conditions are suitable.
AT WHAT STAGE OF GROWTH DO YOU TRANSPLANT SEEDLINGS?
One approach to tell if a seedling is ready or not is to wait until it has developed its second set of genuine leaves, however this isn’t always the case. Planting seedlings directly into the ground or placing them in a cold frame before they have developed enough of a root system is not recommended. If the roots aren’t fully formed, the root ball may disintegrate when it’s removed from the tray and transplanted outside. This might damage the delicate young roots of your plants, resulting in stunted growth.
The best way to tell if a tree is healthy is to look at its roots. By gently removing one of your seedlings from the dish, you may check for adequate root development. To remove the plug, the cell tray must be slid open completely. Because it is immature, a seedling’s tendency is to draw up as much of the potting soil as it can from the tray.
It will be easier to remove the seedling if it is underdeveloped. When seedlings are left in plastic pots or trays for an extended period of time, root binding occurs as a result of the roots wrapping around the plug. When you remove the plug from a root-bound seedling, you’ll notice largely roots and little growth media visible, which makes it easy to identify.
HOW TO GET SEEDLINGS WITH OPTIMAL ROOT GROWTH FOR TRANSPLANTING.
When starting your own plants from seed, the following are the three most effective methods for developing a strong root system:
- Avoid compacting the soil by using a bottom watering method.
- Plant in trays that are large enough to allow roots to grow downward.
- If you haven’t yet transplanted your seedlings, pot them up before they get root-bound.
Check out our Seed Starting 101 Guide in the Seed Starting Resource Blog for more information on seed starting.
HOW DO I CHOOSE THE BEST SEEDLINGS AT THE NURSERY?
For a healthy garden, look for a few specific characteristics in the seedlings you buy from a nursery before you plant them in your yard. You don’t want a plant that’s too big for its pot, but you also don’t want it to become root-bound.
- Avoid plants with slender stems and long, lanky stems. These may not be able to survive outside because they haven’t been exposed to direct sunshine.
- Select seedlings that are more compact in size. Once you’ve planted them, they’re ready to grow.
- Discoloration and damage to foliage should be inspected. The color of the leaves should be consistent throughout (unless it is a plant with variegated foliage).
- Check the underside of the leaves for pests like aphids or insect eggs that might be hitchhiking along with the plant.
- Look for symptoms of illness, such as yellowing leaves, brown patches, and dried-out tips, on the plants.
- A few visible roots are fine in the drainage holes at the bottom, but if there are many sticking out, your plant may be root bound.
- Look for moss or symptoms of fuzzy mold on the soil’s surface to identify a problem. Old stock or overwatering can potentially result in weak transplants, as evidenced by these symptoms.
- Squeeze the pot’s sides. In order to tell if there is any loose potting soil left, it should bend slightly when you press down on it.
- Make sure the potting mix is moist but not sopping wet, since too little moisture is equally as bad as too much. When seedlings have too many roots, they might become hydrophobic and struggle to absorb water.
- You should look for plants with simply leaves and buds. Even if given greater space, vegetables and fruits that have already begun to flower and ripen will remain little.
SHOULD I FERTILIZE MY SEEDLINGS BEFORE I PLANT THEM?
In most cases, additional feeding isn’t necessary for seedlings to thrive. Seedlings may become weak or seeds may not germinate if the growth media is overloaded with nutrients. If you use a well-balanced potting mix that includes some aged compost or worm castings, you can give your young plants all the nutrients they need to thrive.
A sterile seed starting mix like ProMix, which is made up of coco coir, peat moss, and perlite, may necessitate a light feeding once the seedlings have developed their second set of leaves. This only applies if you plan to keep them indoors after the second set of leaves for an extended period of time.
We don’t want to give out fertilizer advice because every person and situation is different, but choosing a well-rounded potting soil will assist ensure that your seedlings are well nourished. Tomatoes, peppers, cucumbers, and squash can be started in a sterile seed starting mix and then transferred to a larger container filled with a balanced potting soil when they are ready to be potted up. A balanced nutrient profile can be achieved by utilizing this rather than garden soil, which may be lacking in some nutrients.
HOW LONG CAN SEEDLINGS STAY IN CELL TRAYS?
Size of cell tray determines how long seedlings can remain in it. The plant has more room to grow when it has deeper and larger cells. If not allowed enough room to spread their roots, seedlings might become root-bound. Typically, the seedlings are kept in the cell trays for about three to four weeks before being transplanted to a larger container or an outdoor plot. Use a frost blanket if you want to move fragile seedlings outside in the Spring. You can find out more about frost blankets in Frost Blanket: How and When to Use It.
Choosing the right size for a transplant depends on how long it will be kept indoors before it is transplanted into the garden. This will be taken into account when deciding on the best cell tray for the seeds you intend to grow.
HOW DO YOU TRANSPLANT SMALL SEEDLINGS?
The number of transplants that can be grown in a smaller area has led farmers to turn to cell trays as an alternative growing method. Using a plug popper or finessing a seedling plug out of a cell is something that many people have mastered over time. Bootstrap These cell trays are made by growers to make this task easier for the farmers themselves. In this video, you can see how to remove the cell tray plugs.
WHY PLANT SEEDLINGS OVER DIRECT SOWING SEEDS IN THE GARDEN?
The advantages of sowing seeds in cell trays and growing seedlings in the ground are numerous. Weeks before the latest date of frost will allow you to get a head start on the growing season. Planting in cell trays also aids in increasing the quantity of seedlings that may be raised in a smaller area. If you’re growing for quantity, this is a major benefit.
It is also advantageous to develop seedlings for transplantation since it increases the likelihood of successful seed germination. As a result, you’re more likely to succeed in the long run if you just transplant vigorous seedlings. This season, why not try your hand at starting your own seedlings? Learn how to start your own veggies, flowers, and herbs from seed in Seed Starting 101.