The article highlights the warnings from gardening experts regarding the risks associated with using old or stale potting soil for indoor planting. Zane Zeltiņa, the owner of the nursery "Baižas," emphasizes that one should inquire about the source of the soil, specifically whether it is from the current season to avoid using potentially harmful materials. She suggests that if stale soil is accidentally purchased, it can be mixed with garden soil to improve it without negative consequences.

Additionally, the article points out that using stale soil in greenhouses is not advisable as it can lead to plant diseases that are hard to eradicate. Maruta Kaminska, another gardening expert, suggests taking preventative measures in greenhouse soil, such as incorporating microbiological preparations like trichoderma before planting crops like tomatoes and cucumbers to combat fungal diseases. This preventative approach underscores the importance of being vigilant about soil quality in controlled environments.

Overall, the advice given in the article serves as a crucial reminder for gardeners to carefully select their planting materials, particularly in greenhouse settings, to promote healthy plant growth and avoid complications related to soil health.