There are both more than one reason you would transplant stuff growing in your indoor garden, and different ways to go about doing so. The most common reason to move a plant from one growing container to another is that you’ve succeeded in increasing it’s size to a point the it’s simply too big for it’s britches. This happens for both hydroponic gardeners and indoor growers using the traditional potting method.
The first time you’ll need to move your indoor crop will be when seedlings or rooted cuttings have reached a stage of maturity that the starter cell or rockwool cube provides insufficient space for increasing the root ball. This is pretty simple transplanting, especially with the hydroponic rockwool, where you simply maintain good root moisture while transferring the starter cube to bigger blocks or previously hydrated clay pellets. You do have to make sure that you’ve got roots situated deep enough in their new media, and yet not too deep, no matter what growing method you’re using in your indoor garden. Some plants like tomatoes are perfectly happy to generate new roots at the soil-line/planting level. Other crops you might grow in your indoor garden may not be able to deal with it well at all.
Potting up, as transplanting a plant into a larger pot is known in traditional container growing, is just as simple. Place enough fresh potting mix in the new container to give the roots room to develop longer growth, and still maintain the right placement for the current root ball to be adequately covered with media and sit at least 1/2″ below the top lip of your pot.
What About Switching from Soil to Hydroponic Growing?
You can change your indoor growing method? Yes, but there are few reasons a gardener would want to avoid this if possible. Still, if it’s the only way you can obtain starter plants – buying them from a standard greenhouse or lack of funds for every piece of hydro equipment all at once – knowing how to transplant them properly is best.
First of all, you cannot allow any potting medium to wind up in your recirculating hydro system. You’ll have all kinds of equipment problems if it does. So you need to totally clean the roots of all medium, and preserve the existing roots. This can be a simple to tedious process, depending on how big and how complex the current root ball you need to clean is. The younger the plant, the easier this task will be, and on a really mature plant – total potting mix removal may prove impossible when the root system is robust.
I could type this all out in steps, but it will be a lot easier for you to quickly understand how to go about removing all traces of growing media before transplanting plants into a hydroponic setup by watching this short video below.
Remember to hold any plants you have not grown from seed in your grow space in quarantine for a couple weeks of observation to ensure you won’t be introducing pests or disease to your garden at large. The same would be true if you’ve brought a plant from the outdoor garden in for the winter. Its the only way to protect your closed garden environment against a variety of hard to deal with enemies of an abundant harvest.