...

Blog


...

Lars Lund

08 Sep 2020 14:33

Tomatoes should not be irrigated

We nurse our tomatoes way too much.

Photo: Grøn Kommunikation ©

 

They just have to learn to find the food themselves.  

The tomato season has ended. Now it’s time to clean out the greenhouse, and the old plants that no longer yield should be removed. Although a lot of water has poured outside, we have all watered the plants inside the greenhouse. In any case, it’s a necessity if they are in plant pots or capillary boxes, but how essential is it if the tomatoes are in beds in contact with the soil?    

 

Right now, there’s a self-sowed tomato seedling in my greenhouse. A seed has fallen into a gap in the flooring. It has been there for a while and has even had the fate of a small amount of sunlight. The seed had landed just under a plant table. It has neither been watered nor fertilized. Admittedly, it has neither got flowers nor offspring, but it looks quite healthy.

It makes me think of the now 77-year-old Russian gardening author Galina Kazmia. She reports in her books, how she in generations has learned to imitate nature and effectively grow healthy vegetables. Galina Kazmia has, in addition to her long authorship, worked as a chemist and physicist. She is first and foremost concerned with growing vegetables without too much work. 

Galina sows her tomatoes in flowerpots that she makes herself. The pots are 4-6 inches long and 1.5-2 inches narrow plastic rolls with soil. The trick of sowing in pots is to force the roots to move down and not to the sides. Also, she plants quite dense with only 10 inches between each plant. This means that at first, they are tall and thin, but that changes when their roots have reached far enough into the soil. When the tomatoes are planted, they get 5 litres of water to start. The soil is covered by newspapers to retain the water. Afterwards, the plants are no longer watered. If they want water, they need to move into deeper layers of the soil. I guess you say: “that’ll teach them.” Galina plants in flowerpots, and since she has taught them from the tentative beginning, that water is obtained by sticking the roots further into the soil, they will continue developing their root system downwards. The way down can easily be 5 feet.  

 

Swedish horticulturist agrees

The method fits quite well with the method the Swedish horticulturist Kjell Åberg told me when I visited him in Ystad one summer. He thinks we water tomatoes too much. He showed me how dry the soil was in his tomato greenhouse. He only watered sparingly and forced, in the same way, the tomato plants’ roots further into the soil. A trick his father had taught him. According to Åberg it is the growbags that have “taught” us to grow in a way, so we are compelled to water more than necessary.

 Kjell Åberg har lært af sin far, at tomater skal pines

Foto: Grøn Kommunikation ©

 

Hønsefjer som madpakke

Galina har også et tricks ud over vandingstrickset. Hun gøder nemlig også kun en enkelt gang.  Samtidig med at hun udplanter sine tomater, så kommer hun en håndfuld hønsefjer fra en gammel dyne ned i hvert plantehul.  Fjerene gør jorden mere luftig, og indeholder en del silicium, der er med til at styrke bladenes ydre cellelag. Det betyder, at planterne er mindre udsatte overfor forskellige svampesygdomme. Dyrkningsjorden er almindelig god havejord, der hvert år får tilført blade, som let arbejdes ned i jorden. Jorden graves ikke, da det vil ødelægge mikrolivet i de forskellige lag. Herudover laver hun sin egen start gødning, der er en blanding med en spiseskefuld fosfor pr. plante, plus lidt kalium og nogle ikke definerede mineraler, som hun sælger via nethandel i Rusland. Har planterne brug for mere, mener hun, at de henter det længere nede i jorden.

Tomatplanten i mit eget drivhus har sået sig selv, eller jeg har tabt et frø. Planten gemte sig under et plantebord, og har aldrig fået vand eller gødning

Foto: Grøn Kommunikation © 

 

En alternativ gødning kunne være  brændenældegødning. Ud fra en række andre forsøg indeholder nældegødning det planterne har brug for. Tomaterne vil dog næppe kunne klare sig med en enkelt gang gødning, men det vil jo komme an på en prøve. Bliver de lyse, så mangler de i al fald gødning. Eventuelt kan man give et ekstra tilskud ved at bruge sit afklippede plænegræs som jorddække. Plænegræs er rig på alt det, planter har brug for.

Har du selv lyst, til at prøve at dyrke tomater der selv skal klare sig, så husk at du selv skal så tomaterne. Køber du dem færdige til udplantning kan du ikke være sikker på, at rødderne har ”lært” at de skal gro nedad, og ikke ud til siderne. Jeg forsøgte i øvrigt denne sommer at dyrke tomater i haven i køkkenhavens bede. De passede helt sig selv og gav en ganske fin høst.     

Du kan se en video med den russiske haveguru her https://youtu.be/KhBbs7SdD5w

 

Her står en af mine tomater ude i et lille hjørne i køkkenhaven. Den har helt og aldeles passet sig selv.

Foto: Grøn Kommunikation ©

Om Lars Lund

Lars Lund
Danish horticulturist and journalist
Lars Lund has for many years engaged in the garden and greenhouse. Lars has published many books about greenhouses, and he has participated in many Danish horticultural TV shows. He is a walking garden encyclopaedia, and he has answers for most basic cultivation questions – also the more ambitious ones.  

Get to know Lars Lund