solar greenhouse

Farm Support Structures

May 27, 2020

Some crops on the farm have a growth habit that is best supported with the helping hand of a built structure.

Growing pole beans climb the bamboo and twine trellis

One such crop is pole beans, which send out runners to wind their way up whatever they can find. So farm manager Eric Ball and Emily McGlohn built a bamboo and twine structure for the growing bean vines to wind themselves up, though the runners still need a little help to “train” them to find the right places to climb.

A newly built trellis of bamboo and twine for pole beans to climb — April 29

Pole bean seedlings begin to sprout — April 29

Eric built another structure last spring to support blackberry canes. In the first year of growth, the blackberries produce primocanes, which were pruned and managed so that they spread across suspended wires, making them nearly invisible. In the second year, the established primocanes become floricanes, where flowers grow and then bear the fruit Rural Studio Farm is now harvesting.

Flowering and fruiting blackberry canes grown along wire trellis

Because the primocanes were pruned and supported by the wires, the fruit is borne off the canes in easy-to-pick cascades at three-foot and five-foot heights. As the floricanes produce berries, the plants also sprout new primocanes that will be next year’s floricanes. Once fruiting ends, Eric will cut out the spent floricanes and begin pruning and training the primocanes for next year’s harvest.

Blackberries of different stages of ripeness hang from canes

Eric, Steve Long, Xavier Vendrell, and Mary English also built a support structure for determinate field tomatoes so that they will have something to hold them up once they get top-heavy and begin bearing tomatoes.

A view of the newly built tomato cages for determinate field tomatoes

Recently transplanted tomato plants sit within their built climbing structures

Meanwhile, in the greenhouse, plants supported on string-lines—cucumbers, tomatoes, and cherry tomatoes—continue to bear fruit. The greenhouse zucchini has also been extremely prolific

An overhead shot of the east half of the greenhouse, highlighting the various plants

An overhead shot of the west half of the greenhouse, highlighting the various plants

A ten gallon tub overflowing with ripe zucchini harvested from the greenhouse — 1-day zuke harvest: 63.5 lb.s

A large, red, ripe tomato from the greenhouse sits in a workers palm — 1-day zuke harvest: 63.5 lb.s

Tags: blackberries, cherry tomatoes, cucumbers, pole beans, rsfarm, solar greenhouse, tomatoes, zucchini

Don’t Rebuke the Cuke

April 27, 2020

Loads of mature cucumbers hang from the trellised plants in the greenhouse

Like tomatoes, cucumbers are well suited to being grown in a greenhouse where warmer temperatures and the support of vertical growth can produce huge harvests. Eric Ball (Rural Studio’s farm manager) and the students constructed a trellis and began cucumber seeds back at the beginning of March and now their efforts are bearing fruit.

A tray of cucumber seedlings — cucumber seedlings in early March

Students secure a hanging trellis for future cucumber plants — cucumber seedlings in early March

As the cucumber plants grow, Eric pruned off the side shoots so that each plant had a single growing stem, and he helped train the tendrils to grab the trellis. This reduces crowding, promotes good cucumber health and production, and improves ventilation.

Cucumber plants just beginning to climb the trellis in the greenhouse — March 27

Growing cucumber plants in the greenhouse — March 27

Each leaf node produces a side shoot, a flower, and a tendril for climbing.

Picture showing tendril, female flower, and side shoot of cucumber leaf node

Fertilized cucumber fruits begin to grow

Until advances in plant breeding, cucumbers were typically monoecious, which means that each individual plant produces both male and female flowers. This also means that they are in need of a pollinator to transfer pollen from the male flower’s stamen to the female flower’s stigma (this can occur on flowers from the same plant). Since these cucumbers are being grown in a greenhouse, where pollinators are infrequent visitors, this means that ordinary cucumbers won’t set fruit unless hand-pollinated—a laborious and time-consuming activity for these productive and delicate-flowered plants.

Cucumbers hang ready on the vines for harvest

As such, Eric selected a hybrid cucumber variety that is both parthenocarpic, meaning that fruit can develop without being fertilized, and gynoecious, meaning it produces primarily female flowers, since the redundant male flowers would only divert the plant’s limited resources away from fruit production.

A sculpture of a cow made from scavenged scrap metal — iris

Tags: cucumbers, rsfarm, solar greenhouse

Greenhouse Tomatoes

April 10, 2020

Nothing says summer quite like fresh tomatoes. However, because of Rural Studio Farm’s greenhouse, our tomatoes are already setting fruit in early April from tomatoes that students started at the end of January.

Students and Eric talk about greenhouse plans — January

Close-up of green cherry tomatoes — January

A wide shot of plants growing in the greenhouse — March 27

A wide view of greenhouse crops, with prominent tomatoes — March 27

But growing tomatoes in a greenhouse is a little different than in the field. For one thing, there is less space for such sprawling, vining plants to grow. So in the greenhouse, students take advantage of vertical growth by supporting the growing tomatoes with strings dropped from a support line. Then students pruned the plants down to a single growing stem.

Pruned tomato plants in greenhouse pruned to a single stem

Tomato plants produce suckers at the nodes between stem and branch (coming off at about a 45-degree angle) that will eventually grow into separate stems, each producing its own branches and fruit, and students prune these off, sometimes daily once growth takes off. Such pruning produces fewer tomatoes overall, but these tomatoes are larger and more plants can be packed closer together, producing a higher total yield. Students also removed all branches below the first fruit cluster to open up air movement around the disease-prone plants, especially since airflow is limited in the greenhouse.

A tomato plant with suckers identified — Suckers

Tomato plants were pruned toward the bottom to open up air flow — Suckers

Since our farm manager Eric is working solo right now, he also started some smaller determinate tomatoes, which max out at five feet tall, in an effort to try and minimize such high-need practices, since determinate tomatoes require less support and only very minimal sucker pruning (only below the first flower cluster) or else yields are reduced.

Greenhouse tomatoes growing upright with fruit and flowers

Tags: rsfarm, solar greenhouse, tomatoes

“Alla faccia della pioggia”

March 6, 2020

Major progress was made at the Solar Passive Greenhouse this week, despite the rainy weather.

The top of the thermal mass wall was enclosed with metal plates (that resemble the shape of shark’s eggs). The barrels were covered with gravel to maximize the wall’s heat absorption.

We fabricated a new table for the produce weighing station using pieces from the scrap pile.

We also welded handrails to help us climb the barrel steps at the back of the building. These new handrails give better access to the operable windows at the top of the thermal mass wall.

Tags: fabrication, solar greenhouse, thermal mass wall

A Welding Day

February 10, 2020

We welded, we taught welding, we tried welding, we enjoyed welding. And now the back stair on the greenhouse (which gives access to the upper windows for cross ventilation) is DONE!

Tags: back stair, solar greenhouse, welding