How to Graft Double Tomatoes

Acquire rootstocks at a nursery or gardening supply store.

Sow six rootstocks in dated trays one week prior before grafting.

Cut a 45-degree angle one-quarter inch below the cotyledon leaves with a razor blade on each plant grown with the rootstock. Discard the tops of the plants and retain the bottoms for grafting.

Cut the stems of six seedlings in the same way that you cut the rootstocks but retain the tops of the plants and discard the roots.

Clip the tops and bottoms that you retained together carefully with grafting clips. Take care to match the 45-dregree angles together as closely as possible. Mist the grafted plants with room-temperature water.

Place the grafted plants in a dark humid space draped by black plastic and keep them there for four to five days. Mist the plants once or twice per day with room-temperature water. Remove the plants when their tops are healthy and standing up. Discard any plants that didn't take and became droopy or died altogether.

Place the plants in a sheltered location out of direct sunlight for a period of three days. Mist the plants once or twice per day with room-temperature water. Place any plants that don't thrive back into the darkened humid space and monitor them daily to determine whether they will succeed in thriving and growing.