How to Graft Tomatoes
Grafting is the act of joining the top portion of one plant (scion) to the bottom portion of another (rootstock). Grafting is beneficial in tomato production because tomato varieties are rarely both good yielders and disease resistant. Grafting makes it possible to have a plant with both desirable characteristics.
The grafting process most used on tomatoes is called tube grafting. Tube grafting gets its name because of the clear 2-millimeter diameter tube-like clip used to hold the scion on the rootstock until the union is made. Tube grafting is fast and easy…once one gets the hang of it.
There are several “essentials” one needs for tube grafting tomatoes:
- Razor blade: to make the cuts
- 2mm plastic grafting clips: to hold the scion on the rootstock
- 70% alcohol: to sanitize the razor blade and clips
- Healing chamber and shade cloth: to provide humidity and darkness during healing
- Humidifier: to add moisture to the air in the healing chamber
Any variety can be used as a scion source. Rootstock varieties are selected based on their resistance to soil borne pathogens. Both Maxifort and Beaufort are resistant to most everything except bacterial wilt.
Plants are ready to be grafted when they reach the 2-4 leaf stage. The stems of each have to be the same diameter (2mm) to graft. It may be necessary to sow rootstock varieties 3-5 days before scion varieties.
Grafting should be done in an area with low light and mild temperature (75 degrees F); not outside or in a greenhouse. It is also recommended to bring the plants indoors to acclimate 5-12 hours before grafting.
The first step is preparation. Set up the healing chamber with a humidifier and disinfect the working surface, razor, and grafting clips. The healing chamber can be made from a PVC pipe frame, wrapped in clear plastic, and covered with 4 layers of shade cloth. The job of the healing chamber is to prevent the scions from drying out.
Next, with a clean razor and steady hand, cut the rootstock stem at a 45-degree angle (just below the cotyledon leaves) and slide a grafting clip halfway onto the stem. The severed top can be thrown away or propagated.
Next, with a re-cleaned razor, cut the scion stem at the same angle above the cotyledons. The scion can now be slid into the clip already on the rootstock stem. The cuts have to match up!
The newly grafted plants should now be placed into the healing chamber. The plants should be kept in complete darkness for the first week and the temperature maintained at a humid 75 – 80 degrees. During the second week in the chamber, the shade cloth can be removed (one layer a day) and by day four, the humidity reduced. If scions begin to wilt, replace a shade cloth layer and maintain humidity for an additional day.
Finally, after two weeks in the healing chamber the plants can be moved to a greenhouse or sunroom to harden off. After 7-10 days the plants are ready to be planted in the garden. The entire process takes about 5 weeks.
For more local horticulture updates, follow me on twitter: Jacob Searcy@BeaufortCo_Hort
On May 17th, 9 a.m. to noon (rain or shine), the Beaufort Master Gardeners would like to invite the public to their annual “Pass Along” Plant Sale at the Beaufort Extension office. This would be a great opportunity to get the plants you want and the knowledge you need. Call the Beaufort Extension office for more details: 252.946.0111
Gardening Calendar for March
• Pre-emergent herbicides can be applied to lawns when soil temperatures reach 52 degrees.
• Fertilize shrubs.
• Shade trees can be fertilized.
• Emerging spring flowering bulbs can be fertilized.
- Asparagus beds can be fertilized in early March before spear growth begins.
- Ponds should be fertilized starting this month and should be continued for the next 7 months.
• Fruit trees and grapevines can be planted until the buds begin to break.
• Perennial like: columbine, hollyhock, coreopsis, daisy, and phlox.
- Rose bushes can be planted this month.
• Broccoli, cabbage, and cauliflower can be set out in the garden around mid-March.
- Beets, Carrots, Chinese cabbage, kale, kohirabi, lettuce, Swiss chard, turnips, and potatoes can be planted anytime this month.
• Start annual flowers and summer vegetables inside.
• Perennials like cannas, daylilies and Shasta daisies can be divided at this time if the ground is dry enough.
• Prune fruit trees.
• Wait for spring flowers to fade before pruning them. Pansies for example will flower longer if older flowers are removed.
- Roses can be pruned later this month.
• Overgrown shrubs can be severely pruned if needed, except for needled evergreens.
• Landscape shrubs can be sprayed to control the following pest: euonymus-scale, juniper-spruce spider mites, and hybrid rhododendron-borers.
• Spray all fruit trees with dormant oil to eliminate some insects. This is especially important if the tree has just been pruned.
- Spray apple and pear trees with streptomycin while they are blooming to help control fireblight.
• Check gardening equipment to make sure it is in good working order.
- Consider buying gardening supplies like fertilizer, insecticides, and fungicides while there are still adequate supplies.
• Consider ordering new varieties along with tried-and-true varieties to see how they compare. Experimenting with varieties is fun and has virtually no ill effects.