There are plenty of products available at garden stores that claim to rid plants of pests or mold and other diseases. But these products are of dubious origin: even the organic sprays have unintelligible ingredients. Plus, they can get pretty expensive for the avid home gardener. It’s very easy to make your own spray repellent for either rot or pests, and in most cases, it’ll save you a trip to the store.

Fungus, mildew and rot – whichever term you use – can decimate an entire crop. But if you catch it early enough, it can be eradicated before you are forced to pull up too many plants. Try spraying one of these mixes, getting both the tops and undersides of the leaves.

• Two tablespoons baking soda in a quart of water. 
• A one-to-one mix of milk and water (milk is full of good bacteria, which is why it and yogurt are such powerful fungus killers ).
• Cooled chamomile tea.

Insects can be another garden terror. They’re pretty hungry for such tiny little dudes. There are various ways of getting rid of them – oil-based repellents just make it hard for them to land or lay eggs, while the more astringent concoctions aim to kill.

• Canola oil mixed with few drops of liquid soap. Ivory soap tends to be the go-to, but if you don’t have that on hand, it won’t hurt to try a different variety .
• A mix of hot pepper sauce and a few drops of soap. Let it stand overnight before spraying, and remember to shake it first.
• If that doesn’t work, try this ruthless murder spray: smashed garlic bulbs, smashed chili peppers (or a few tablespoons chili powder), vegetable oil, liquid detergent, and a few cups of water. Experiment with the proportions if it doesn’t work right away, but anticipate a huge decline in your pest population.

Even though these sprays are made with common household products, they are pretty powerful. Be sure to only use them after dusk, as the liquids make the plants susceptible to burning. And don’t forget the preventive measures gardeners can take to help prevent disease and pests from the start: Seaweed and fish fertilizers contains elements ...