Growing plants from seed allows gardeners to raise more types of vegetables, herbs, and flowers at home. A seedling nursery can make it easier to keep plants organized and monitor growth before they’re transplanted outdoors or into containers. There’s room for seed-starting trays under a 20 Foot Dome along with other gardening projects.

Building a Seedling Nursery

Greenhouses don’t need extensive equipment to grow young plants from seed. It’s helpful to have growing media, clean containers, light, moisture, and temperatures that meet each crop’s needs. Planning your layout carefully can allow you to grow seedlings from early germination through the nursery stage.

Select a Location for Seed Starting

Before setting out trays and planting containers, choose where your seedling nursery will be located in the greenhouse. Pick a spot that’s convenient for watering seedlings and accessing trays when you want to move them.

If possible, leave crowded areas of mature plants out of the seed-starting space. It’s easier to keep track of trays this way, and you won’t risk damaging seedlings while you work around larger vegetation.

Take note of how sunlight reaches your greenhouse during the day. Seedlings need light, but positioning will vary based on season, crop selection, and conditions inside the dome. Don’t set out trays in a place where taller plants will block available sunlight.

Leave room to carry trays safely and move around tools without disturbing neighboring plants.

Select Your Seeds Based on Gardening Goals

Choosing seeds is a matter of climate, season, and space. For example, some vegetables do well when starting in trays and others prefer to be direct sown.

Common seeds for starting indoors include:

• Tomatoes: Plants that are often started in trays then transplanted when weather permits.

• Peppers: Many varieties benefit from getting a head start and warm soil for germination.

• Lettuce: Can be direct sown or grown in trays, depending on your garden plan.

• Cabbage-family crops: Some, like broccoli and cabbage, do well when started in trays.

• Herbs: Basil and other herbs are great for starting indoors when you want to grow them in containers or beds.

Read the seed packet to determine germination temperatures, depth for sowing seeds, spacing, and expected maturity dates. Growing information will guide you on when to start specific crops indoors and how many seedlings you need to plant.

Take care not to overwhelm your growing space by starting too many seeds. Plan for how much space each crop needs at maturity and leave room for those plants.

Use Clean Trays and Proper Containers

Seed trays, small pots, and individual cells make it easier to organize seedlings while they develop. Starting seeds in containers with individual cells also helps move seedlings during transplanting.

Containers should be clean and provide drainage. If reusing trays, wash them before filling with soil. This is particularly important if you’ve used trays that previously held diseased plants.

Choose a seed starting mix made for germination instead of using heavy garden soil from outdoors. Seed starting mix should retain moisture without leaving the medium soggy. Ideally, excess water drains away, and air can reach developing roots.

Fill trays and containers without compressing the soil too much. Follow instructions on the seed packet for depth, then label trays with both the crop name and date planted. When growing more than one variety of seedlings, clear labels eliminate confusion.

Manage Moisture for Germination

Moist growing media helps seeds begin to germinate, but excess water creates issues as well. You want to keep the soil evenly moist without leaving it waterlogged.

Water seeds gently after planting so they don’t get washed away. If planting in small cells, use a fine spray to keep moisture even.

Keep an eye on your trays so you can water when necessary. Shallow containers will dry out faster than deeper pots. Temperature, airflow, and growing media all play a role in how quickly you need to water seedlings.

Some seeds require humidity covers to improve germination, but others have different requirements. If using a cover on your trays, monitor them for the crop you’re growing and remove or adjust the cover once seeds begin to germinate.

Ensure that water isn’t collecting beneath trays for extended periods. This helps with root health by providing proper drainage.

Provide Suitable Light and Temperature

Temperature and light play significant roles in seedling development. Each plant has specific needs for temperature and light intensity, so refer to the seed packet or another growing guide.

Once seeds begin to germinate, vegetables and most flowers need ample light to grow strong stems. Without enough light, seedlings may develop long, weak stems that struggle to support themselves. Place trays in an area with adequate light. If seedlings begin leaning, rotate their position to compensate.

A thermometer can help you track temperatures under the greenhouse covering. Temperature where plants sit under the greenhouse can heat up quickly on sunny days. Even if the air temperature feels cool, it may be too warm for young seedlings.

Use grow lights to supplement if your plants aren’t receiving enough sunlight. Follow manufacturer recommendations for distance from plants and daily light durations. Adjust as necessary to meet your plants’ needs.

Maintain Airflow and Humidity Levels

Airflow should be adequate to prevent constant damp conditions without causing stress to young seedlings with intense drafts. Air circulation helps leave foliage dry, which can promote healthier plants.

Open vents or doors to regulate airflow when necessary. Track temperature and humidity levels instead of leaving the greenhouse sealed during hot, sunny days.

Avoid overcrowding trays or pots so much that leaves heavy overlap. Space allows for easier inspection of individual seedlings and makes watering simpler.

Clean up any spilled growing media and remove dead seedling leaves. Check for discolored leaves, thin stems, unusual spotting, or other issues. If you think a tray may have a disease issue, isolate it from other seedlings until you’ve properly diagnosed the problem.

Organize Trays by Date Planted

If starting multiple crops at staggered dates, organization is key. Arrange trays by crop, planting date, or when you plan to transplant seedlings so they can receive proper care.

Consider keeping a simple nursery notebook with the following information:

• Crop and variety

• Planting date

• Notes on germination

• Watering or fertilization notes

• Planned transplanting period

Labels and records help you quickly identify varieties that take longer to germinate. Planning ensures you know when growing space will open up for new seedlings.

Stable shelving or benches can help organize your space if it works with your greenhouse. Make sure shelves can support the weight of wet trays and aren’t positioned where they’ll impede movement or airflow.

Prepare Seedlings for Transplanting

Seedlings can be transplanted once they have ample growth and conditions are right for moving them outdoors or into a larger space. Check the plant’s development and use guidance for that variety instead of a predetermined number of days from planting.

Gradually introduce many plants to outdoor conditions before transplanting. Hardening-off seeds takes several days and involves slowly increasing their time in direct sunlight. Follow instructions that match your crop selection and outdoor temperatures.

Handle seedlings gently during transplanting to avoid damaging stems and roots. Water appropriately after transplanting, then monitor your plants for any signs of stress.

Clean containers, remove finished trays from your seedling nursery, and prepare the area for future use.

Choose Your Greenhouse for Seed Starting Projects

Dome Greenhouses has greenhouse options for gardeners planning a dedicated structure. What works for your household depends on space available, climate, and what you wish to grow. Explore our products to learn more about how greenhouse covers can support gardening projects like starting seeds indoors.

Conclusion

Organizing a seedling nursery is a great way to ensure you care for plants starting from seeds. With clean containers, suitable growing media, consistent moisture, adequate lighting, and proper airflow, managing seed-starting trays can be simple. The structure of a 20 Foot Dome allows you to fit several trays of seedlings while leaving room for other garden projects. Track planting dates, check seedlings often, and adjust environmental factors to meet each crop’s needs.

FAQs

Q1: What can I start from seed in my greenhouse?

A1: Tomatoes, peppers, lettuce, cabbage-family veggies, herbs, and many other types of plants you are able to grow from seed.

Q2: Do seedlings need direct sunlight?

A2: Yes and no. Seedlings require sufficient light. However, some seedlings do fine on good natural sunlight while others require supplemental grow lights during low-light situations.

Q3: How often should I water seedling trays?

A3: Monitor your growing medium and water when necessary to keep the medium around seedlings at an appropriate moisture level. Don't let seedling trays get waterlogged or allow young seedlings to dry out completely.

Q4: When are seedlings ready to transplant?

A4: That depends on the type of crop, the growth of the seedling, and your growing conditions. Consult variety information for more detailed information and be sure conditions at your destination will befit the plants as well!

Q5: How do I keep my seedling nursery tidy?

A5: Label your trays with what you planted and when. Place seedlings that will be planted around the same time close to each other. Record keeping is good, leave room for watering and examining your seedlings.