The Double Cup Method
updated 11/18/24
To grow hot peppers using the double cup method, you will use 2 Solo cups per plant, one inside the other. The outer cup acts as a water reservoir. The roots will grow out of the inner cup and dangle into the water of the outer cup. This prevents the roots from becoming root bound which can be a problem with pots. Also, because the soil is not getting wet, you reduce your chances of harboring insects like gnats and developing fungus or disease. Watch the Video below!
Double Cup Materials
- 2 Solo cups per plant. 18oz cups are preferred but you can get away with 16oz. (you can also do one square bottom cup & one round bottom*). They don’t have to be Solo brand. No clear cups.
- Soil. Suggestions below.
- (optional) Tags. I like the Vigoro Plastic T-Labels at Home Depot or these on Amazon. These work well when you plant outdoors! Wooden popsicle sticks tend to absorb water and get moldy. Or you can just write on the cup with a marker.
- Seeds. You do have seeds right?
- (optional) Pizza savers (video below) *not necessary if using square/round bottom cups.
Best Soil For Hot Pepper Plants
I recently did a study comparing FoxFarm’s Ocean Forest vs Happy Frog soils (among others) and the results might shock you! I won’t spoil the surprise, but I discovered that these soils do not require fertilizer (while they are indoors for 2 months)! That’s right, no need to spend time and money on fertilizing your plants indoors. This is a HUGE benefit that (in my opinion) definitely justifies the price. I was also able to germinate seeds directly in these soils too.
Happy Frog is a little cheaper than Ocean Forest but either will do. Or you can do a mix of both! For Long Islanders, check out Agway in Mt. Sinai, NY.
Other Soil Options
I have used PRO-MIX Premium Organic Garden Soil (yellow bag) with good results. This is just a basic blend of peat, perlite, and mycorrhizae. I did need to fertilize however. They also sell a red “moisture” garden mix but I’ve heard of people having drainage issues with that one.
You can also make your own soil by mixing some organic compost, peat moss or coco coir with perlite. I like to get a 5lb bucket and fill it 3/4 with compost and add about a solo cup of perlite. Perlite helps with water drainage. If you use straight compost it will compact and water will not flow through. And if you use too much perlite the water will flow through the dirt too quickly 🙂 I stay away from top soil since it is far too dense and tends to harden.
A common mix for all types of plants is 1/3 peat, 1/3 vermiculite, and 1/3 perlite. I am currently researching how to transition to coco coir due to it being a renewable resource.
Check to see if the soil you use contains fertilizer and if it doesn’t, you’ll need to add your own.
Labels & Tags For Hot Pepper Plants
You can write on your tags with permanent marker. Or, if you want to reuse your stakes year after year, you can print on labels on Avery printable labels (make sure they’re good for outdoors). I use labels from onlinelabels.com using their Maestro label designer. Make sure you use a laser printer and waterproof labels. Black ink will withstand fading the longest in direct sunlight.
I like the Home Depot Vigoro T-label tags but the T-type tags from Yinkin are my absolute favorite. Some people write on upside down plastic spoons too. I wouldn’t suggest wooden popsicle sticks since they tend to absorb water and get covered in white fuzzy mold.
ALWAYS take pictures of your plants in the beginning of the season. This way if your labels get misplaced or the ink fades you’ll know what they are!
How to Start Pepper Seeds in Double Cups!
As you probably already know, hot pepper seeds can be somewhat unpredictable when it comes to germinating. I recommend planting 3 or more seeds (minimum) in each cup to ensure germination, since waiting around for 3 weeks will cut into your season if nothing grows and you need to start over.
*Video Updates
*If the soil you choose doesn’t contain fertilizer you will need to add it yourself either to the soil or in the water of the outer cup.
*Push the seeds in about 1/2 inch into the soil, otherwise they might sprout with the shells stuck on their heads, a.k.a. “helmet heads”.
*Only water the soil if your soil contains fertilizer. If you are adding fertilizer to the water in the outer cup then you don’t need to get the soil wet at all.
Seeds started in double cups do not require potting up! They can stay in their Solo cups while they are indoors (2 months max) before transplanting outdoors.
Separating the Double Cups
The cups will nest inside each other with the dirt in the inside cup and the water in the outer cup. You’ll need to find a way to prop up the inner cup so that there is a 1-2″ gap between both cups. Some people put rocks in between. Some people use a Solo cup with a square bottom for the dirt and a cup with a round bottom for the outer cup. Or – use pizza savers!
Best Temperature For Hot Pepper Seeds
Put them in the warmest room of your house. Hot pepper seeds germinate best when the soil temp is between 65-95 degrees, 80 being the optimal soil temperature. You can use a meat thermometer to check the temp (remember to wash it afterwards :). You can also use heat mats to raise temps by 10-15 degrees if you need the extra warmth. Some heat mats even have a thermostat built in so you can dial them in precisely!
Watering Hot Pepper Seeds
Check on the seedlings once a day. Make sure the soil has not dried out. Make sure it is moist, not wet. Moist! I use a spray bottle (or even a turkey baster). I reuse an empty gallon (milk, iced tea) jug, fill it with tap water, and let it sit for 24 hours uncovered to allow the chlorine to evaporate and the water to come to room temperature.
Adjusting the PH of the water isn’t really necessary for plants that will live inside for only 2 months.
Do Hot Pepper Seeds Need Light?
They don’t need light until they start to sprout. When they do sprout you will need to start giving them light asap or else they will get tall and “leggy”.
How Long Do Hot Pepper Seeds Take To Germinate?
In optimal conditions you can expect germination in about a week or so. Superhots, like the Carolina Reaper can take around 2 weeks (and some up to 4 weeks!) so be patient. It’s very exciting to see the little sprouts emerge from the soil (right?). Typically for me, if I do not see sprouts in 10 days I will start another tray as a backup. You don’t want to wait too long in case you screwed something up, since starting over at this point is going to take away from your growing season.
Another trick I have used is to sow your superhots (reaper, ghost, scorpion, etc) one week before you sow your regular peppers (cayenne, bell, poblano) this way you can expect them all to germinate around the same time.