May in the greenhouse

In May, the mildness settles in the garden and in the greenhouse the temperatures rise. Freshness is still possible, so stay vigilant and ventilate in case of heat. The gardener’s season has started again so plant, repot, cuttings,…

Take cuttings, transplant, the work of May in the cold greenhouse is not lacking
Take cuttings, transplant, the work of May in the cold greenhouse is not lacking


  • In mai, the cold can still rage in certain regions, especially at night, which implies a significant thermal amplitude with sunny days during which the temperature can soar under the windows. Ventilate the greenhouse as much as possible during the day in good weather.


  • Water very regularly because daytime temperatures can quickly climb in the greenhouse!

  • Be particularly vigilant with recently transplanted plants and seedlings that will not tolerate any water shock.

  • Resume watering cacti and succulents every 10 days.


  • Have fun at cut as many plants as possibleit is the ideal season and the protection of the greenhouse will promote their recovery, so you will have many plants to install in your garden and on your balcony.

  • Cut Mint in a simple glass of water. There are many species and varieties, exchange them on Jarditroc and complete your collection!


  • Wash seed trays and seed cups with bleach before reusing or storing them. Start disinfecting the tutors that will soon be back in service in the same way. Pathogens can remain dormant there all winter, hence the importance of disinfecting them before reusing them.

  • Do the same with secateurs and all tools with a blade. Take the opportunity to sharpen them and grease the mechanisms. A clean and straight cut avoids many phytopathologies!



  • It’s still a good time to try some transplants on fruit trees, enjoy!

  • graft the azaleas in half-lunge, the catalpa in crown, the rosebush in crest with pushing eye, le ginkgo en chip-budding.


  • Continue regular fertilizer applications after heavy watering so as not to burn the roots. Select the right fertilizer according to the type of plants. Indoor plants grown for their foliage need more nitrogen. Flowering plants of potash and phosphorus just like vegetables!

  • The fertilizer can also be selected according to the cycle of the plant, this is the case for orchids to which a fertilizer with a higher nitrogen content will be added during the formation of the leaves or pseudo-bulbs, then a fertilizer rich in potash and phosphorus to ensure flowering.

  • Start fertilizing your cacti again, they should soon bloom abundantly!



  • If it hasn’t already been done, install shades or paint the windows in Spanish white.

  • Watch out for slugs and snails that could creep into your greenhouse and destroy your young plants. Repel them with natural methods or harvest them manually to release them into the wild. One trick is to thread a disc of sander sandpaper around the base of the seedlings. Slimes won’t come near it!

  • And whiteflies or les thrips begin to develop, do not hesitate to release auxiliary insects which will get rid of them. If an isolated plant is really affected, take it out of the greenhouse, cut and burn the affected parts and treat with fern manure. Keep the plant in a sheltered place in the garden and think about repotting it because generally plants that are suffering are more affected by parasites!

  • Take care of the hygrometry rate to avoid invasions of red spiders (mites). In the event of an attack, water the foliage of your plants outside, let them dry and then treat with fern manure.



  • Continue repotting or topdressing operations. Always choose a soil of excellent quality corresponding to the real needs of the plants (special potting soil for cactus, citrus fruits, green plants, flowering plants…).

  • Repot in their final pots the bulbs put to force the previous months. glorious, tuberous begonia, lys or grand dahlia will be ready to join the balcony after the ice saints. If you prefer to plant them in the ground, wait for the right moment without going through the pot stage.


  • Transplant your seedlings tomatoes, melons, gourds, courgettes, eggplant, peppers et cucumber in buckets 10 cm in diameter. Choose a quality horticultural soil and add an organic root stimulator to promote good rooting and the future vigor of the plant.


  • There is still time to sow tomatoes, peppers, eggplant, peppers, pepinos, gourds, cucumbers, tamarillos, watermelons, kiwanos et courgettesbut hurry, it’s really the last moment!

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Source: Au Jardin, conseils en jardinage by

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