Should You Add Sugar to Mother-in-Law's Tongue?

Adding sugar to mother-in-law's tongue has become a popular tip, with claims that it can stimulate microorganisms in the potting mix and boost the plant's vigour. There is some truth behind the idea: sugar provides a readily available source of carbon for microorganisms. However, it does not target beneficial organisms alone, and may also encourage fungi, unwanted bacteria and insects. As a result, it is neither necessary nor particularly advisable for keeping this plant healthy.

What is sugar added to a mother-in-law's tongue pot supposed to do?

Supporters of this method say that small amounts of sugar feed the microbiota living in the potting mix. Some microorganisms do use simple sugars for energy, contributing to the breakdown of organic matter and the cycling of nutrients.

That does not make sugar a fertiliser for the plant itself. Mother-in-law's tongue makes its own carbohydrates through photosynthesis, while its main requirements from the potting mix are water and mineral elements.

• Sugar supplies carbon to microorganisms in the potting mix;
• It does not provide balanced plant nutrition;
• It cannot replace nitrogen, phosphorus, potassium or micronutrients;
• There is no known need to add sucrose to the pot;
• Reports of more attractive leaves after using it are anecdotal rather than a guaranteed result.

Why can feeding soil microorganisms become a problem?

Sugar in the potting mix cannot distinguish between helpful bacteria and fungi and those that may create difficulties. A concentrated carbon source can quickly raise microbial activity, use up oxygen and encourage fermentation, particularly in a damp pot with limited air circulation. This is an especially unsuitable environment for mother-in-law's tongue, as its roots are quite sensitive to excess moisture.

Does sugar make mother-in-law's tongue grow faster?

There is no strong evidence that sprinkling household sugar into the pot makes the plant grow faster or develop firmer leaves. The species, now classified as Dracaena trifasciata and formerly known as Sansevieria trifasciata, is naturally a relatively slow grower. Its development depends chiefly on suitable light, healthy roots and a balanced supply of nutrients.

For more reliable healthy growth, the following care measures are far more predictable:

• Keep the plant somewhere with bright indirect light;
• Allow the potting mix to dry before watering again;
• Choose a pot with drainage holes;
• Use an airy potting mix that does not stay waterlogged;
• Feed sparingly during the growing period when needed.

Why can sugar also attract ants and fungus gnats?

Leftover sugar on a moist surface can provide food for insects and increase microbial activity at the top of the pot. Fungus gnats are mainly linked to damp potting mixes rich in decomposing organic matter, while ants may be drawn to accessible sugary sources.

• Avoid leaving sugar crystals on the soil surface;
• Do not keep the pot permanently wet;
• Remove decaying leaves and other debris;
• Check the potting mix if small insects appear;
• Do not try to revive a weakened plant by adding more sugar.

The best care for mother-in-law's tongue is still to avoid overdoing it

Mother-in-law's tongue became popular precisely because it tolerates dry spells and needs comparatively little maintenance. Its most common problem indoors is almost the opposite of a lack of sugar: overwatering can leave the roots without enough oxygen and encourage rot. Letting the potting mix dry between waterings is usually far more important than adding kitchen ingredients.

The sugar trick has a possible microbiological basis, but that does not make it a gardening necessity. Indiscriminately feeding the microorganisms in the pot can lead to unpredictable results and does not give the plant complete nutrition. To maintain firm leaves and healthy growth, appropriate light, effective drainage, moderate watering and balanced fertilising remain safer approaches than scattering a spoonful of sugar over the potting mix.