When Is It Safe To Start Growing Seeds In Greenhouse

If you’re worried when it is safe to start growing seeds in a greenhouse, mark your calendar and sow six weeks before the last frost date. Depending on your region, you can even start growing vegetables as early as February. Knowing your state’s hardiness zone will also be a huge help to identify the conditions and frost dates more accurately. 

One of the things that newbie gardeners must learn is how to start growing plants in a greenhouse. You can start with seeds or transplants, and if you choose seeds, you must ensure that they won’t experience harsh conditions. After all, environmental conditions heavily influence the germination of your plants.

When Is It Safe To Start Growing Seeds In Greenhouse

When Is It Safe To Start Growing Seeds In Greenhouse For Success


Frost dates

It is safe to start growing seeds in the greenhouse six weeks before the last frost date. How do you identify the last frost date? The hardiness zone of your state will help you know when to expect it. You can even see when the expected first frost date is for more natural planning of the greenhouse’s growing season. 

You must be thinking about why you can’t start your seeds too early. After all, you’re using a greenhouse anyway, and its main advantage over outdoor cultivation is control of temperature and humidity. While that is true and those two factors are influential in planting growth, remember that you are starting with seeds. 

You can start seeds in the greenhouse anytime, but assuming that you will later transplant them, it’s best to launch six to eight weeks before the last frost date. It would help if you also remembered the light conditions in the greenhouse, which affects the time you can start growing seeds. For example, you have to wait until the middle of February because of the low light during winter if you’re in the northern US.


Temperatures and seasons

Another reason why you need to grow seeds before the last frost date is to ensure that the temperatures in the greenhouse for seed germination are optimal. The University of New Hampshire mentioned that the best temperatures to ensure germination is from 65° to 75°F. However, remember that different plants also vary in their optimal germination temperatures. 

The season is also crucial for the greenhouse. Remember that because of its design, it can get freezing at night. In this case, it’s ideal to use a seedling heat mat to warm the soil consistently. Putting the factors mentioned altogether, most gardeners opt to plant in early spring.


How To Grow Seeds In Greenhouse

Before you start sowing, you need to check if there are specific instructions for the seeds beforehand. For example, some seeds require overnight soaking, scarification, or stratification. Then, you can use open flat trays or individual plug trays in the greenhouse. 

Growing seeds in open flat trays and single-cell trays have different steps. For the former, you want to plan the spacing of the seeds so that it’ll be easy to thin the plants later on. Afterward, transplant the seedlings into individual pots when they produce their first set of true leaves.

If you opt to plant one or two seeds per cell, you can keep them in the tray for longer. This is because you don’t have to worry about the plants not having enough space for their roots. Still, you can transplant your seedlings later on when needed. 

Would you need to buy a special seed starting mix for the greenhouse? The good news is that you can create your potting mix using peat moss, perlite, and compost. Be aware of the proper ratio between them and sterilize your potting medium to prevent diseases. 


Other Factors To Consider When Growing Seeds In Greenhouse

Besides the frost date, temperature, seasons, and light, water and oxygen also influence the seeds’ growth in the greenhouse. Remember, seeds won’t germinate without water, and as the seeds germinate, the need for oxygen also increases. In the greenhouse, you can ensure that you can meet these requirements. 

For water, it’s crucial not to give too much or too little. Too much water causes rot, and too little water can kill embryos. Instead, aim to provide continuous germination by misting the seeds and covering them with peat moss to prevent drying. 

The seeds respire, and this increases as they undergo germination. To meet the rising need for oxygen, you need to ensure that the media you’re using drains well. The mix shouldn’t be too heavy nor wet. 



Sowing seeds should not be intimidating for a newbie gardener, primarily through the help of the greenhouse. However, you must know when it is safe to start growing seeds in the greenhouse. In general, it’s better to sow six weeks before the last frost date because seeds are more sensitive to harsh conditions. 

This is why it’s worth planning your growing season by checking your frost date using your state’s growing zone. Since you’re growing in the greenhouse, it also puts you in the advantage of adjusting the ideal temperatures to ensure germination. Afterward, follow the growing guidelines given by university extensions to guarantee that your seeds will thrive. 


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How To Prevent Root Rot In Hydroponics: 3 Useful Tips

If you’re a newbie gardener who’s looking to find ways to hone your skills, you’d want to learn how to prevent root rot in hydroponics even before this problem affects your plants.

Hydroponics can be advantageous to crops in more ways than one. However, it also comes with risks of diseases, such as root rot, which can be destructive or even lethal to your plants.

Unfortunately, there are no effective methods to recover the wilted parts that were affected by the root rot once it hits your plants. The only thing you can do if you do not want this catastrophe to befall your crops is to prevent it before it happens. Read on to learn more about this subject.


What is Root Rot?

Root rot is a disease that attacks the plant roots and causes them to suffer decay. This usually happens when a lack of oxygen supply occurs in the substrate.

To give you an idea, think about plant roots that are submerged in water that only has a little oxygen in it. Over time, the plant suffocates and dies.

Aside from rot and decay, this disease also leads to the proliferation of fungi that are naturally present in the soil. These include Rhizoctonia, Alternaria, Pythium, Botrytis, Fusarium, or Phytophthora. As soon as fungi colonies start to grow, they tend to target the weakened roots and infect your precious plant babies.

Once the plant becomes infected, they won’t be able to take in what they need to grow – water, oxygen, and other nutrients. When this happens, it won’t be long before the plant dies.


What is Hydroponics?

In case you’re not aware, the term hydroponic is derived from a Latin word that means “working water”. To put it simply, hydroponics is an art that involves growing various types of plants without soil. If you’re like most people, the first thing that comes to mind when somebody talks about hydroponics would be a picture of plants with roots suspended into the water without using any type of growing medium.


Avoiding Root Rot in Hydroponic Systems

Detecting and identifying root rot can be tricky. When your plants get infected, their leaves and roots gradually wither until the whole crop itself dies from the lack of nutrients, which is a common symptom of many diseases.


What causes root rot in hydroponics?

One of the requirements in hydroponics systems is oxygen. Without it, your plants are basically on the road to death. On the other hand, lack of such is one of the major triggers for root rot, and it must be avoided at all costs.

Just like when planting in soil, you loosen up the ground so that your plants’ roots can have their required intake of oxygen. That is the case for crops grown in aqueous solutions as well. If they cannot breathe, they would not be able to grow.

Another agent for root rot is the temperature. The last thing you would want in your system are parasites that leech nutrients intended for your plants and infect the water during the process. In common terms, these fungi are called molds.

One of the best breeding grounds for these is warm and moist areas. For this reason, if the water temperature inside your reservoir is high, then you are susceptible to it. Something as minor as letting the solutions exposed to sunlight can already be a risk factor.


3 Useful Tips on How to prevent root rot in hydroponics

There is good news! Root rot in hydroponics can be prevented! Just follow these tips:

Tip#1: Use the right air pump

If you do not want root rot to affect your plants, you merely have to avoid its causes. If you need oxygen, keep the water bubbling by providing an air pump of appropriate size, and also give importance to proper ventilation in the room.


Tip #2: Maintain the temperature

The temperature should be maintained within the 70 to 80 degrees F range. Get rid of any materials that can make your system vulnerable to infections, and make sure not to disturb your crops while they are trying to grow.


Tip #3: Get rid of the rotten parts

However, if you failed in preventing the disease, then the rotten parts should be removed immediately. Cut them off as there is no chance of reviving them, and focus on the potential new growth instead. Fix your hydroponics system and eliminate the risks.


Why Give Greenhouse Gardening a Try?

Greenhouse gardening offers numerous benefits to greens aficionados who dare to take their gardening experience to the next level. Aside from acting as a shield against the effects of inclement weather, a mini, hobby, or semi-pro greenhouse can also serve as a protective layer that keeps harmful bugs and critters at bay.

What’s more, its enclosed structure allows you to control your plants’ growing conditions including the temperature, light, moisture, and ventilation of the greenhouse’s internal environment. With a controlled environment, you’ll be able to extend growing seasons and grow plants that aren’t native to your area.



No matter how well-informed you are about how to prevent root rot in hydroponics, you cannot completely eradicate the risks. Therefore, to avoid the worst-case scenario, you should be prepared to sacrifice the infected for the sake of others. While you’re at it, consider trying your hand at greenhouse gardening as well.


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