Technical Protocol 3.0

Greenhouse Planting of Tissue Culture Transplants

Well-rooted plantlets in plastic boxes with air vents can be transplanted with high success rates following this protocol.

General Guidelines


The primary sign of an effective transition process is greenhouse acclimated plantets within 7 days. To accomplish this it is very important to make sure that the plantlets never ever wilt, not even a single leaf should wilt. At the same time, plants need to adjust to greenhouse conditions, so minimum extra misting or fogging should be used. We have formulated this protocol based on our own experiences and those of our customers, to be inexpensive, versatile and highly successful. We have even been able to transition plants to open field conditions, using this type of approach.

Shipping is stressful

We do not recommend transplanting to soil immediately upon receipt of plantlets.

Upon receipt, each plantlet box is opened, plantlets are sprayed with a mild antitranspirant, the entire shipment is covered with seedling cloth and misted lightly with water. Over the following 2 days plantlets are misted lightly as needed while they recover from shipping.

Transplant to soil gently

After 2-3 days, plantlets are removed from the agar and planted into soil. Weaker plantlets, such as Million Bells, may need a full dip in antitranspirant, other plantlets need just another light spray. Plantlets are watered in thoroughly, set on benches and covered with the seedling cloth. Hand misting is all they need. Heavy mist is not recommended.

Transition should take a week

After 2 days the seedling cover cloth can usually be removed. Check the plantlets 2-3 times for the first few days and mist by hand lightly as needed. If plantlets show any sign of wilting, replace the seedling cover cloth and hand mist. Drench the trays daily as you would for seedlings.


If you prefer to use mechanically misted benches, please use the finest droplet size you can and set the mist for infrequent short bursts. Waster sitting on the leaf surface delays the cuticle development and the plantlets will take longer to get adjusted to open bench conditions.


We recommend Cloudcover (Easy Gardener, Waco, TX) as a suitable, light antitranspirant. We use the recommended rate: 10% of the concentrate in a water spray. We will include a bottle of Cloudcover with large shipments.

General Principles

The purpose of the transplanting protocol is to push the plantlets into independence as quickly as possible, while not allowing them to wilt, EVER. If the weather is hot, or very dry, time the planting in the greenhouse for the early evening or late afternoon hours, to minimize the first day shock. After 3-5 days, check a few of the plantlets for signs of new leaves and root tips. As soon as there are new white root tips it is time to remove the black shadecloth. As soon as there are new leaves it is time to remove the white seedling cloth. Generally, remove the coverings at night, even the first day, to keep the air fresh and reduce disease. Never use automatic mist at night, it encourages disease, slows growth and creates leaves with no effective cuticle.
This method was used in California in August to field plant 1/2 acre of watermelon plantlets with 17 days between the laboratory and the field and losses of less than 5% in the greenhouse and less than 1% in the field. It was 108F when we planted the greenhouse and it was 105F when we field planted, so this method can work very well.

This method was used for potatoes in Chile with very good results, even after the plantlets had been in dark shipping conditions for over 1 week.

For less extreme climates we recommend removing the black shadecloth as early as possible.

Daily Recommended Schedule

(Suggest you print for reference)
Day    Time    Day     Notes
-24 PMArrival Take plantlet boxes to the greenhouse, open lids, spray the plantlets with Cloudcover, lightly place lids on top of the boxes for the night, cover with Seedling Cover Cloth (white 30%), left open at the ends to let some air through.
-17 AM__________ Open box lids entirely, loosely cover the boxes with seedling cloth.

NOTE: if conditions are dry, may need about 5ml water in each box, otherwise dries out a little too quickly and agar may get too hard to remove easily.
07 AM__________ Soil Mix:
  • 8 pt. Supersoil (fert. booster included)
  • 4 pt. perlite
  • 1 pt. vermiculite (#2 grade)
Remove plantlets from the plastic boxes, wash agar off, trim roots to about 1 inch.

Dip shoots in 10% Cloudcover solution to cover upper and lower leaf surfaces.

Plant so that about 1/4 inch of stem is beneath the soil surface and all roots are submerged. (Note: Never leave the newly planted trays in the sun or without drenching with water when going on breaks or lunch).

When a tray of plantlets is full, apply a thin layer of Vermiculite to soil surface and drench the soil to make a good root-to-soil contact throughout the plug.

Cover transplants with Seedling cloth (white 30%) and mist the cloth so it is lying directly on the upper leaves of the plantlets.

Cover entire plantlet plug tray area with 30% black shadecloth suspended or supported 1-4 inches above the seedling cloth and again mist from above to wet.

If the greenhouse is unshaded, cover entire plantlet plug tray area with 30% black shadecloth suspended or supported 1foot (25cm) above the seedling.
 1 PM  Manual misting
 5 PM  Final spray for the day with fine water mist
110 AM_________ Manual misting
 3 PM  Manual misting
 6 PM  Manual Misting
211 AM_________ Replace seedling cloth covers for the day, mist lightly.

Should be able to see small 1/8 inch white root tips apparent on few plantlets lifted up out of the soil.
 4 PM  Remove shadecloth and seedling cover for night.
310 AM__________ Water plantlets and replace seedling cover for the day, mist lightly
 6 PM  Remove shadecloth and seedling cover for night.
411 AM__________ Water plantlets and replace seedling cover for the day, mist lightly
 6 PM  Remove shadecloth and seedling cover for night.
510 AM__________ Should be able to see some newly expanded leaves.
Water in plantlets and replace seedling cover for the day.
 6 PM  Remove shadecloth permanently
610 AM__________ Water plantlets and replace seedling cover for the day/td>
 6 PM  Remove seedling cover for night.
810 AM__________ Roots should be coming out bottom of trays, new leaves expanding rapidly.
98 AM__________ Fertilize with general mix (15-15-15 Peters)
Does not require anymore cloth covers
Water in mornings as needed
Should not require any misting
Keep in full sun on top of bench.