You just received a new box of yCubes - how exciting!
If you already have mature plants on your Gardyn and/or plant food in your tank, it's critical to follow the 10 refill tips below. This is because plant food not only hampers germination, but it can hurt sensitive, young sprouts.

1. Discover Your New yCubes
If you open the box and don't see your complete order at first, lift up the layer of cardboard to find more yCubes underneath! We pack them tightly to reduce movement during shipping, and help use less packaging.
2. Make sure your Sprout Nursery is clean
Whether it's fresh out of the box or your old favorite, be sure to hand wash your Nursery with soap and clean water to give your yCubes the freshest start in life.
If you already have yCubes germinating in your Nursery and you recently washed it, you can skip this step. If you aren't using a Nursery, opt for a small tray and ensure it is clean.
3. Add your yCubes
Using the Nursery's tray, insert up to 10 yCubes. Remove the small cardboard cover on individual yCubes, and don't add any yCovers or Pod Caps.
4. Keep your yCubes Hydrated
When properly hydrated, the rockwool in your yCubes will have a mottled appearance with darker green spots. Find your scenario below to learn how to best hydrate your yCubes, and remember:
NEVER add plant food to your Nursery, and only add more water once it is completely gone.
- If you already have yCubes and water in your Nursery, only add more water if it is completely gone. To do so, follow the next step.
- Add tap water (no plant food!) until it reaches the fill line inside the Nursery tray, which is the lower indentation in each tray square. Use the photos below to help you find the perfect level. While it might be tempting to add more water, too much will hurt, not help your seeds, so stick to our guide for best results.
Germination Water Levels
1. 2.
3.
Germination water levels that are: 1. Too low 2. Just right 3. Too high
- If you are moving wet yCubes from your Gardyn to the Nursery, and your Gardyn had plant food in it, rinse your yCubes well with just water to remove any plant food. Then, place your yCubes in the Nursery without adding more water.
- If you are moving wet yCubes from your Gardyn to the Nursery, and your Gardyn DID NOT have plant food in it, simply place your yCubes in the Nursery without adding more water.
5. Cover with the Nursery's Vented Lid
We designed the Nursery to help you germinate new yCubes 30% faster than other methods, but it's not complete unless you add its vented lid! The lid helps optimize temperature and humidity levels for your seeds and sprouts to help give them a germination boost.
If you're using a tray, we also recommend adding a lid with holes in it to mimic the benefits of the Nursery's lid.
6. Monitor Moisture
Check your Nursery's water level daily, and only add water once it's completely gone. If you placed wet yCubes in your Nursery, only add water only once they are almost all light green in color or feel very light when picked up.
If a yCube appears similar to the image below, it has too much water. No need to worry, though! Let it sit without water in your Nursery (or on a tray with a vented lid if you have other yCubes that still need water in your Nursery). By the time this yCube needs more water, it should be sprouted and ready to place on your Gardyn!
Oversaturated yCube
7. Watch for Sprouts & True Leaves
Sprouts is a general term for the first leaves, or cotyledons, that grow from the seed. These leaves are the reason sprouts don't need plant food: the cotyledons provide all the nutrients a plant needs in this first growth stage.
Germination times vary across varieties and even between seeds of the same plant. Some varieties can take up to 28 days to germinate! For variety-specific information, you can look up each of your plants in the Plant Book.
True leaves are the second leaf set that grows, and they resemble the mature plant's shape on smaller scale. yCubes are ready for your Gardyn and plant food once they have established their true leaves, are 2 inches tall, or have roots growing outside the yCube.
8. Thin your Plants
If your yCubes are ready for plant food and the Gardyn, they're also ready to be thinned! This is a critical step to choose the strongest and tallest sprouts that will then thrive without competition for resources within their yCube. Thin fruiting plants and leafy greens down to 1, and most herbs and flowers to 3.
Find our thinning recommendations for each of your varieties here!
9. Plant your yCubes
Once your yCubes have true leaves and are thinned, it's time to add them to your Gardyn!
Always hand wash your yPods before adding a new yCube. Then, insert yCubes with true leaves into the yPods until they're flush. The yCube's orientation doesn't matter!
10. Freshen Up
Top off your tank with fresh water and 1/2 teaspoon of plant food per 1 gallon of water added. Alternatively, pamper your newly added yCubes (plus the rest of your plants) with a full tank refresh!
Either way, be suer to always follow our plant food usage guidelines.
Now you can keep growing using your yCube refills! Follow Kelby's guidance, and maintain a fresh balance of water and plant food to watch your Gardyn thrive. Order yCubes any time, directly in the app, for year-round harvests. Happy Gardyning!