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If you own an AeroGarden it can be a valuable tool to help you get a jump on starting seeds for your outdoor garden. Even if you are just getting started, it is not too late! As long as you have 100+ days left until your first frost date, you can have a nice growing season. I am just about to get started myself.
Why Should I Start Plants from Seed?
Many gardeners may opt to buy seedlings from a local garden center. And that is fine, and fast. You can often buy them and plant without much prep work. And if you have a smaller garden, that is a great way to get a fast start. However, starting from seed nets you more for your money. And, from what I have seen over the past couple of years in gardening groups and when visiting my local Home Depot and Lowes, prices of starter plants have gone way up. Starting your own seeds saves a lot of money and gives you access to varieties that may not be at your local garden center. Depending on your area, one starter plant could cost $4, although you can sometimes get 3 plants for the same price. But, for that price, you can get one or two packs of seeds that can start 40-50 plants or more. Lettuce and carrot seeds sometimes come with 200-300 seeds in one pack! And the seeds would cost even less if you head to the Dollar Store! Check out this list of my favorite seed sites.
Traditionally, gardeners have direct sowed seeds outside, or started them inside in a windowsill, or under grow lights in soil. But, if you own an AeroGarden you can jumpstart your seed starting and get more done in a shorter period of time.
Why Should I Purchase the AeroGarden Seed Starter?
AeroGarden offers seed starting kits for every model that they currently sell. I picked up at least one (or more) for every model that I have to be able to start all of my garden seeds. The seed starter allows you to sow a lot more seeds at one time than the normal AeroGarden deck. And your seeds will likely germinate faster and grow faster than in soil. You can start more seeds in a small amount of space.
| Unit | Normal Deck | Seed Starting Deck | Notes |
| Sprout | 3 | 15 | 10 watt light, some seeds like peppers may start a bit slower |
| All Harvest Models (excluding Harvest XL) | 6 | 23 | 20 watt light |
| All Bounty Models | 9 | 50 | Bounty Basic – 30 watt light Bounty – 40 watt light Bounty Elite – 50 watt light |
| All Farm Models | 12 | 85 | 60 watt light, If you have a 2-sided Farm you can purchase one seed starter for each side |
Visit the Amazon AeroGarden store (while supplies last) to order a seed starting deck for your unit. Be sure you order the right one for your model. Unfortunately, you will not find any for older units.
When Should I Start My Seeds?
The date that you start seeds will depend on your area. For me early – mid March is a good timeline. If you have at least 100+ days or so in your growing season, you have plenty of time to start your garden from seed. You can start peppers, tomatoes, eggplant, herbs, leafy greens, and many other things inside and have nice strong seedlings ready to go out when the weather breaks.
Figuring out when to start your seeds for the outdoor garden can be a tricky process. This is especially true if you are a new gardener starting in soil and/or you decide to start them in your AeroGarden. If you are not in a hot climate, be careful not to start your seeds for outside summer crops too early. I know we get excited, but it is not always necessary. You will be amazed how quickly the plants grow… especially in hydroponics. Starting too early will mean you will have a jungle in your house before it’s time. LOL!! Also, you may have to pot up your seedlings several times instead of just once. If they stay in the small nursery pot for too long the roots will get bound and the plants may be unhappy.
Find Your Last Frost Date
To determine the date that you should start your seeds, check your zone and frost dates at Almanac.com, read your seed packets, and go from there. Seed packets will say things like Start indoors 8 weeks before your last frost date. For reference, I’m in the Chicago area, zone 6a (recently changed from 5b). The last frost date in 2023 was April 27. And this year the frost date actually changed to April 30 from the last time I checked it a few weeks ago. This means that I can supposedly safely plant out after that date. But… that is hardly ever the case. It is best to wait at least 2 weeks after your last frost date to plant.
Seedlings grow faster in hydroponics. So, when starting seeds in AeroGardens if you want, you can safely cut off about 1-2 weeks from the time that it tells you on the seed pack for most plants. Why? Seeds start faster and everything grows like weeds in the AeroGardens! Hydroponics just about always grows faster than soil.
However, I would say peppers can stay on the same timeline. Some of those take a long time to germinate and take off. It may take a bit of trial and error to get the perfect timing. But, plants are forgiving, and you will still get goodies if you are close. I have adjusted my timeline over the past few years.
In 2021, I started seeds in my AeroGardens on April 3rd. As they grew too large for the seed starting trays, I moved them out to nursery pots with seed starting mix under grow lights. I planted out on May 16th… So that was 6 weeks. I could have planted out a bit sooner based on the size of my plants, but it was way too cold in Chicago. We still had temps in the 30s and frost. Plants were a great size by then.
In 2022, I started my peppers on March 14th. I wanted to give them extra time since some peppers take longer to germinate. I started my tomatoes on March 16. I did not see a huge difference in my harvest yields because of the earlier start dates.
In 2023, I started my peppers on March 13. I started my tomatoes on March 18. By they time I planted them, most were a great size! And I am going to check the seeds packs on my other vegetables and herbs and see if I need to start any of those earlier. Some herbs and veggies say to start them about 8 weeks before planting out. That is 2 months, so that is right now (counting ahead to mid-May) for me. Now, there are some exceptions to this. For example, if you have the space to keep them inside and want to plant out larger plants, you can start earlier. This is what those with very short growing seasons (looking at you Alaska) do to make sure they will get a harvest before it starts to get cold. And they have prepared for it by having a greenhouse, or plenty of room inside to house those plants while they wait for the weather to be right outside.
How Do I Start the Seeds?
Starting seeds in your AeroGarden is easy. When you purchase an AeroGarden seed starting kit it will come with sponges and nutrients. You just add your seeds. Do it just like planting your AeroGarden for indoor growing. The only difference is the cages are built into the deck. You just need to drop the seeds in the pods, and watch them grow!
A couple of tips…
1. Do not add nutrients right away. Yes, it says to do so in the AeroGarden manual. However, seeds do not need them. Seeds have everything they need inside to germinate and push through. I add nutrients after most of the seeds have germinated. This cuts down on the risk of algae since the pods are not covered as they are on the regular deck. Algae is caused by light mixing with the nutrients. You will notice green on your sponges, or in the tank. It is not harmful in small bits, but large quantities can kill small seedlings. So, skip the nutrients until 1-2 weeks after your seedlings have sprouted.
2. Invest in some communion cups. The seed starting trays do not come with domes. They are not 100% necessary. But, they do help speed up seed germination by providing humidity. The communion cups fit perfectly on all models except the Sprout. They are perfect because you can remove them individually as needed. Remove them before the seedlings touch the dome.
3. Download my AeroGarden seed starting logs to keep track of what you are planting. No one wants to guess what they planted. And no need to scribble on random paper. Just print these, or use a PDF filler.
WHEN DO I MOVE THE PLANTS TO SOIL?
As mentioned, plants grow pretty fast in AeroGardens. If it is still chilly outside, you will have to pot them up. This means moving them to nursery pots, or similar and keeping them under good grow lights. The average timeline to pot up tomatoes seems to be about 4 weeks. Peppers… about 4-5 weeks (unless they take a while to germinate). Why? At that time, mid-April, it is still way too cold here in the Chicago area to put plants outside, or even to put them in my unheated greenhouse.
When transferring your AG started plants from hydroponics to soil there are 2 very important things to remember! The plant is used to living in water. So to successfully transfer it to soil you have to wean it off of living in water. You do that by watering the heck out of it for the first few days of the transition. Like… the soil should be super wet. Once it adapts (after about a week) you can back down to a normal watering schedule.
Planting up is easy. Get some good potting soil or seed starting mix. Fill your nursery pots about half way. Then carefully pull your seedlings out of the seed starting tray leaving it in the sponge. If you planted more than one seed per pod, now is the time to carefully split them. It’s ok if you lose some roots. As long as there are plenty left the plants will be fine.
You will notice how long and strong the hydroponic roots are. This is a perk of starting in hydro. We do not get to see this in soil.
Beautiful right? Now, they go down into the pot. You may have to curl the roots up a bit. Then backfill with more soil. Press down to secure the seedlings. Put the pots in a 1020 tray or similar, water them very well, and put them under a grow light for the next few weeks.
When Can I Move my Plants Outside?
As mentioned above, it is safest to wait at least 2 weeks past your last frost date before planting outside. This is a great buffer for any crazy weather that may come your way. Also, you do need to harden them off. In addition to being used to water the plants are used to living indoors in a protected environment. There is no real sun, just artificial light. There is no wind, no rain, and no elements. They have been pampered. Just like a newborn baby, they need an adjustment period. This works much better with younger plants. This is why we do not start plants too early before our outdoor season starts. If they are too established (large and fruiting) they will be more upset when moved.
And do not let this year’s weather fool you. We have had some nice days. It has been much warmer than usual, but things can change at any time. It is important that you do not move summer plants out until the lowest night time temps are at least 50 degrees for a few days.
What is Hardening Off?
Hardening off means slowly introducing your plants to outside weather and the elements. There are a couple of ways. Traditionally, this would be done over several days. In short, we put them out only a few hours a day or so in the shade, then take them back in the house where it’s safe. The next day you leave them out a bit longer. And so on and so forth. Each day you increase the light. The process works of course, but is a long process.
I started doing the shortened process a couple of years ago. Listen… once my plants are out, I do not want them back in the house! So, I wait for a shady day, or I put up my patio umbrella to block the bright sun. I put the plants out on the table, and leave them! I keep close watch. But, as long as it is not super hot outside, and the sun is not beaming directly on them this works. I also have a greenhouse, so I have the option of putting them in there if the weather takes a nose dive.
Some say they do not harden off. And that might work if the weather is still cool (like high 50s – 60s), and over 50 at night and it’s cloudy. But… throw plants out in the heat of summer or directly in the sun and they will not be happy. If you take pampered inside plants outside and expect them to just make it the hot sun they will wilt, get sunburn, and may die. Sometimes they recover. Sometimes they do not. So, it is not recommended that you skip the hardening off process.
And yes, depending on timing you can move the whole AeroGarden bowl outside to harden off your plants. This will not work out well for plants started early because they will likely be too big to stay in the seed starter after about 4 weeks. But, if you start some plants about 4-5 weeks before planting out, go ahead and move the AeroGarden bowl outside.
Once your plants appear used to being outside, go ahead and plant them in their permanent homes. After that, water them in, and watch them grow.
On the Facebook group, there have been a few posts suggesting “hardening off” by taking the aerogarden bases outside with the cones included. Do you have any thoughts on that?
Yes! Thank you for asking. I edited to include that information. You can do that as long as the plants have not been in the seed starter too long and they are not too big. I move my plants out after about 4 weeks. But, if I start another round of plants after that, then yes. I will just sit the whole bowl outside to keep from having two pot them up. Works fine. 🙂