Tips for Growing Royalstar Tomato in the Greenhouse

Tips for Growing Royalstar Tomato in the Greenhouse

Royalstar-Tomato-Sakata‘Royalstar’ is an indeterminate cherry tomato that grows well hydroponically in the greenhouse. It works great for harvesting on the vine and loose picking, and its eye-catching rich orange color is sure to attract eyes. Trialing results have proven an excellent flavor profile, desirable fruit firmness, good resistance to cracking, and strong truss versatility.

Tyler Hoopes, Protected Culture Specialist U.S./Canada for Sakata, says growers can expect Royalstar to display 13-gram fruit on average, with vine potential showing consistent clusters and fruit size. It is a great option for growers who want to use one variety for both loose picking and cluster harvesting.


Royalstar is a strong plant with short leaves. A high head density of 4 to 5 is necessary, and a flat temperature regimen to achieve enough stretching of leaves is recommended. A durable, long-cycle root stock is also a proven strategy for high-tech greenhouse environments planning to produce for nine months or longer. Furthermore, a general tomato hydroponic fertilizer mix can be is used, but it is imperative to your yield to reach a higher electrical conductivity (EC) as harvest and light levels increase. This step up in EC will allow the plants to absorb more water, enhancing fruit size and yield. Hoopes recommends monitoring your crop through lab analysis of leaf tissue and influent/effluent fertilizer water.

Carefully monitor generative or vegetative behavior. Continue pulling a new leaf in between each cluster to promote more generative behavior. Keep a maximum of 10 clusters per stem, otherwise the plant will suffer from the high fruit load. Additionally, ensure a sharp drop of temperature during pre-nights, encouraging the crop to respire and increase photosynthesis efficiency. Success depends on the greenhouse, grower, and sowing period, as Royalstar is a strong but generative variety.

Royalstar has high pathogen resistance to tomato mosaic virus, fusarium wilt, fusarium crown and root rot, and leaf mold. It has intermediate resistance to root knot nematode. Pest and disease problems always depend on the environment brought with each season, the greenhouse structure, growers’ practices, and other factors, so it’s best to scout often and treat when needed. Hoopes advises to keep an active climate when growing, as Royalstar is a compact and dense crop that is sensitive to mildew when the climate is inactive.

Hoopes’ Recommendations for Growing Royalstar Tomato Successfully:

• Fertilizer: A general tomato hydroponic recipe, increase EC as harvest and light levels increase.
• Propagation: Grafting is recommended for long-cycle crops.
• Plant growth regulators: Not necessary.
• Lighting: Has shown to perform well under high-pressure sodium lighting.
• Pinching: At the propagator, it is a standard practice for most growers in Leamington, ON, Canada.
• Growing media: Rockwool is a standard growing media, but other substrates can be used such as coco peat.
• Irrigation: Variable timing drip irrigation is recommended.
• Planting/Scheduling: For a grafted crop, sowing is recommended six to eight weeks before the greenhouse is prepared for transplanting. The grower must determine the plant size desired from the propagator. This can affect timing. First harvest can be expected about eight weeks after transplanting.