The vine is unfolding and providing natural shade in the greenhouse. Photo: Grøn kommunikation ©

The plants grow and need water, for the sun is sharp.

By Lars Lund
l@rslund.dk

The drought has hit us, but not in the greenhouse. Here, there is never a drought because watering is part of having a greenhouse, and all the greens are really getting it started. At my place, it is especially in my green roof, the vine, that has long been teasing with a big growth and now is holding its promise. It is really lovely, as the leaves are in full swing providing some much-needed shade.

Pollinating the vine

In late May, the vine produced clusters of flowers. Every morning when I greet my plants, I give the vine a special loving pat. It needs that because vine needs to be pollinated, and in nature, that happens with the wind. In the greenhouse, there isn't much wind to do the job. Instead, I become the wind and shake the large vines. When the very small flowers fall off, some people get startled. They often ask why the flowers are dropping. The simple answer is that even apple trees and other fruit trees lose their flowers, and yet they still produce fruit.

Like in previous years, there is once again the prospect of a bountiful harvest. I can't eat my way through all the grapes, and when my neighbours, who water my greenhouse during vacation, have received their share, I make juice out of the rest. The juice is the most delicious treat without any additives but mixed with sparkling water or blended with a dry white wine, it's also quite good.

Just remember that vine juice can ferment if it's left standing for too long. I discovered this when I arrived at my summer house one day. I had forgotten a bottle of juice on the kitchen counter. The bottle was shattered and its content all over the kitchen walls. Not exactly the plan and what if it had exploded while someone was in the house? In other words, if you want to store the vine juice, freeze it. If you want to know how to prune your vine, read more here.  

New leaves on the olive tree

My olive tree, which is planted in the ground and not in a pot, lost many leaves for the first time during the winter in its nearly decade-long life. Fortunately, it's now thriving again, and new fresh leaves have emerged.

Olives like to have water but can't tolerate overwatering. Especially older trees prefer to dry out, but they need watering while they're forming the actual fruit. Young trees must not dry out for too long.

Here, too, I look forward to harvesting olives to prepare delicious summer dishes.

Read more about caring for olives here: Take care of your olives and citrus in the summer sun.  

Chilli plant survived the winter

My chilli plant, which survived the winter in my bathroom, were pruned in March, and now they are once again meters high and starting to produce flowers. The advantage of letting capsicum survive and not discarding the old ones is that they quickly start bearing fruit. They don't need to spend a lot of energy creating a new root system or a new stem. However, you should pinch off the first flowers that form. This will encourage even more flowers to come. A more drastic approach is to trim the top down when it becomes too tall and spindly, and you can do this multiple times until you have a strong and bushy plant that can support itself. It might be a bit painful, but you'll get a better plant out of it and a higher yield. If you're not brave enough to do it, try with just one plant, and you'll do it forever.

Also read this related article: A chilli and pepper guide for spring 

The tomatoes are outdoors

Currently, I'm not growing tomatoes indoors, but outdoors. Out in the open, they take care of themselves, and they've just been planted. These are special varieties that can handle the slightly harsher outdoor climate. Traditionally, 'Gemini' is an outdoor variety, but the one I have the best experience with is 'Bloody Butcher.' Despite its somewhat bloody and slightly macabre name, 'Bloody Butcher' is a superb tomato. Most tomatoes can be harvested approximately 80 days from sowing to the first harvest, while 'Bloody Butcher' only takes about 55 days from sowing. 'Bloody Butcher' is, therefore, a very early and hardy tomato variety, suitable for both greenhouse and outdoor cultivation. It produces perfectly round tomatoes, juicy and blood-red both on the outside and inside. They reach a diameter of about five centimeters and have a good and intense tomato flavour.

Pinch the tomatoes

If your tomatoes have become leggy, it has likely affected flower formation. If they shoot up too quickly and excessively, perhaps due to lack of light, the first flowers are set higher up on the stem. On the other hand, if they are on the cooler side, the plants become more compact, and the flowers start lower down, resulting in space for even more flowers that will later become delicious tomatoes. Excessive heat also affects the flowers. Remember to pinch off all the small side shoots that emerge in the corners (except for bush tomatoes) and remember to tie up the tomatoes.

Most importantly: the strawberries

In stores, you can almost get fresh strawberries all year round. Mine are also ready. I always have a few pots of strawberries, just like a few buckets of potatoes. In the beginning of June, we harvested and ate the first potatoes, and for dessert, we enjoyed our own strawberries. In many stores, you can buy a special pot where you don't dig up the potatoes but pick them and let the plant continue to grow. They are called potato pots, among other names. They also come in large green tarpaulin bags, where you can open a flap and pick the potatoes. Some of these bags are made of jute and are suitable for both potatoes and carrots. You can also easily make them yourself with two larger plastic pots and a hobby knife, cutting squares in the innermost pot.

Also read this related article: Growing Potatoes in Containers 

Beans for spider mites

The last of my vegetables (beans, and corn) have now been planted after sprouting in the warm greenhouse. I leave a couple of bean plants together with the cucumbers. Spider mites and cucumbers are a combination that is not always easy to deal with, but beans beneath the cucumbers help. The spider mites go for the bait, the beans, and leave the cucumbers alone. Otherwise, spraying cold water under the leaves can alleviate many infestations, as well as using neem oil.

Also read this related article: Get rid of lice before spring 

Air, Heat, and Water

Three challenges in the greenhouse are to provide some shade, ensure sufficient ventilation, and have easy access to water.

You can create shade with a climbing vine that grows up under the roof. Of course, you don't want to shade the entire greenhouse with the vine, but perhaps just half of it. Another solution is Julianas roller shading blinds. They are easy to install with a couple of suction cups. Give them a drop of soapy water to make them adhere better.

A luxury version I saw at the Chelsea Flower Show in late May was a type of external roller blinds made of small teak wood slats. You can get bamboo roller blinds that resemble them. They require a system with a pulley and a wheel that is screwed onto the exterior roof ridge of your greenhouse. Read more about how to provide shade for your plants here: Provide shade for your plants 

When it comes to heat, ventilation is also necessary. It's another way to get rid of excess heat and reduce the risk of many plant diseases. You can hardly ventilate too much.

Water, and more water. That's what most plants need right now. There are different options for optimal irrigation, for example the Juliana Vanlet irrigation system with drip hoses, capillary boxes or seep hoses with a watering timer, so the water doesn't run constantly. Finally, there's, of course, rainwater collection.

Read these articles for more inspiration:

Self watering boxes - easy and convenient 

The amazing world of water.