18 Jan 2024 10:26

Planning the summer season of 2024

With a brand-new calendar year comes the time to plan the upcoming season in the greenhouse. To do so, we always begin by looking back, before making new plans. In this process, we assess what went well and what didn't go so well. Nevertheless, we have already taken care of the first spring preparation in autumn. In this article, you can read more about our plans for 2024 to get inspired for your own greenhouse.

An Early Start

In the autumn of 2023, we planted a lot of flower bulbs in both our greenhouses. In fact, we planted around 300 flower bulbs in total, including tulips, narcissus, and smaller bulbs like crocus, squill, and snowdrops. We wish to use our Juliana Orangeri 21.5 m2 as soon as the sun warms it up in spring. The first bulbs should showcase their beautiful flowers in March, and by then, it will hopefully be warm in the greenhouse during midday.

We have planted flower bulbs in our fixed flower beds, as well as in plant pots and containers. When the bulb flowers fade, we will replace them with vegetable plants.


Evaluation of 2023

In many ways, 2023 was a special year. We experienced a historic drought in the spring, and the summer of 2023 was globally one of the warmest ever recorded. Temperature records were broken in many places in Europe and the rest of the world.

What impact does the climate have on our greenhouse? A clear indicator of the climate change that we were experiencing at Spirekassen, were pests. We have never experienced such a severe attack of aphids as we did in 2023. The dry and warm spring made the aphids thrive in both our greenhouses, and they were difficult to control. Finally, when the ladybugs emerged something changed, as ladybugs are the aphids’ natural enemy, and most species of ladybugs feed on aphids.

By late summer, the aphids were finally gone from both greenhouses. However, the early summer was terrible, and we lost several plants due to the aphids.

However, we fear that some aphids have overwintered in the greenhouse and will start breeding again when the warmth returns in spring. Our hope is to prevent this by thoroughly cleaning the greenhouse in early spring. Additionally, we will introduce beneficial insects into the greenhouse as a preventive measure to create a natural balance between pests and beneficial insects from the beginning of the season.

Hopefully, the cold winter at the end of 2023 helped with the pest problem in 2024. Frost, especially hard frost, simply kills overwintering pests and works almost like a thorough cleaning in the greenhouse.

Additional Shade

It cannot be emphasized enough – good shade options are a necessity in any greenhouse, big or small. Last year, we thought we had good shade solutions, but it turned, that the solutions were not efficient enough after all.

In 2024, we are going to add additional shade and even plan on sewing a few curtains ourselves. It is absolutely necessary that we get control over the climate because neither plants nor people thrive in an overheated greenhouse.

In 2023, we definitely did not have control over the greenhouse climate in connection the tomatoes in our self-watering containers. They suffered early from blossom end rot.

In 2024, the focus will therefore be on additional shading options, and we will completely stop having self-watering containers in our greenhouses from next year.


Selecting Fruits and Vegetables for 2024

Last year, the chilli plants grew in the greenhouse's warmest spot, but this year, we're replacing the chilli with eggplants. We have made this decision because bell peppers and chilli belong to the aphids' favourite plants, and we are hoping to avoid problems with aphids in 2024.

Instead, we are introducing the Ethiopian eggplant 'Rosso Di Napoli' and the eggplant 'Bambino.' Both varieties are organic and require a lot of heat.

In general, we are very fond of colours, so we will also experiment with the tomatillo 'Purple,' used in the Mexican cuisine. Another heat-demanding crop that fits perfectly in the warm corners of the greenhouse. In 2024, we will exclude tomatoes from the Juliana Orangeri, because it is simply too hot for them. When the climate is too warm for tomatoes the fruit setting as well as the harvest is often poor. That is why, the tomatoes will be moved to the old orangery, where we cultivate a combination of cut flowers and tomatoes.

The space previously occupied by our self-watering containers will this year be taken up by a single melon plant. The climate in our Juliana Orangeri is warm and provides the optimal growing conditions for the melon. Already in the autumn of 2023, we planted a Kiwi plant in our old orangery. We hope the Kiwi plant will bear fruit in 2024.


Flowers Take Over in 2024

In general, it is smart to have flowers in the greenhouse. The scent of flowers attracts pollinating insects, which are necessary for pollinating our vegetables and fruits.

We are reintroducing a classic in the summer of 2024. The passionflower was popular in the 1990s, mostly as a potted plant, but it thrives really well in the greenhouse during the summer. Passifloraceae is a family of flowering plants containing about 750 species divided into around 27 genera. They are all very different.

Passiflora caerulea is the one we know best and also the one we want to give new life to in the greenhouse. The species does not produce edible passion fruits. Those come from the species Passiflora edulis. However, passiflora caerulea's growth is massive, and its tendrils can grow up to 25 meters long. The flowers are fantastic and give the greenhouse a tropical atmosphere. Passiflora caerulea is also interesting because it is relatively cold-resistant. If the plant is sheltered, it can withstand temperatures down to minus 10 °C. The climate has changed since the 1990s. Our winters have become milder, and this could have a significant impact on the passionflower. It might be able to overwinter in the greenhouse and sprout again in 2025. That is, what we would like to test.

In our old orangery, we have already prepared the floral display for 2024. We have sown hardy annuals in autumn 2023, and they are already sprouting. The growth of the small plants stops in the winter cold but will pick up again when the warmth returns in spring 2024. Autumn sowing makes early flowering possible – maybe already in early June.

The flowers we have sown in autumn:

  • Larkspur, Delphinium consolida
  • Love-in-a-mist, Nigella damascena
  • Clary sage, Salvia viridis


Advice for the New Season
  • Evaluate the past greenhouse year.
  • Plant strategically: plant heat-demanding species where the greenhouse is warmest.
  • Plant tomatoes where it is coolest and most shaded.
  • Keep an eye on the greenhouse climate and consider optimal shading options.
  • Plant flowers that attract pollinating insects.
  • Introduce beneficial insects from May and onwards.

Om Spirekassen

Christine Wiemann is a greenhouse grower and an agricultural technician and owner of the seed company Spirekassen. Christine is an author of several books about lifestyle, garden life and plant cultivation. Today she writes blogs and shares her knowledge and passion for greenhouses. Christine is a greenhouse expert and an ambassador for Juliana Drivhuse.

Get to know Spirekassen