In the spring and early summer, Green Forest is our favorite romaine lettuce. It grows well and has a lot of tasty juicy crunch, so is welcome as an alternative to soft baby salad mixes of winter and early spring. It takes only 56 days from direct seeding to maturity, yet is a good size (for us, that means not too small). It has a good dark green color, tolerates tipburn moderately well and resists corky root (we haven’t knowingly had that).
There was a Romaine Lettuce Cultivar Trial by Dave Spalding and Timothy Coolong from the University of Kentucky in spring 2008. The variety trial compared 16 romaine lettuce cultivars and one green leaf cultivar. The 16 romaines were Coastal Star, Fresh Heart, Green Forest, Green Towers, Ideal, Jericho, Mirella, Nautilus, Paragon PIC, Parris Island, Plato II, Rubicon, Torrento, and three varieties with only numbers, not names: EXP T12, PIC 714 , PIC-A.
Green Forest had a head weight just over 2 pounds, was the fourth tallest of the 16, and was in the middle of the pack as far as core length (long cores are not wanted, generally).
The trial found the lighter color of Jericho unacceptable (see photo below), although the trade-off with heat tolerance has many of us very happy with Jericho these days. Furthermore, the under-rated Jericho was the heaviest and tallest variety grown. Ideal was also a lighter shade of green, while the rest were very similar to each other.
The trial report notes:
[The] “characteristics of commercially acceptable Romaine lettucecultivars are head weights of about 1.5 pounds, head height or length of 10 to 12 inches, and a core length of less than 3.5 inches. Based on these characteristics, PIC 714, Green Forest, Ideal, and Green Towers were the highest rated cultivars”
For us in central Virginia, Green Forest will not be a suitable variety for the really hot weather, but we do enjoy it while we can. We sow it again in late summer for fall outdoor harvests, and in the hoophouse in winter. It works well as a variety to be harvested by the leaf in winter, but that’s not the topic for July!
Once we get to late June, we use shade cloth over our transplanted lettuces, at least for the first few weeks.
When hot weather arrives and we still want green romaines, we switch to Jericho. You can see the complete Twin Oaks Lettuce Planting Log which I posted a while back.