Where does all the water go!

In recent years, we seem to have been experiencing more downpours than gentle rain showers. So what happens to the water in a garden during such a deluge?

Water percolates into the ground at varying rates depending on the nature of the soil. This is a complex process but for average garden soil, not too much sand and not too much clay, water soaks in at about 4.8 mm/hour. Some water can accumulate on the surface but beyond another millimeter or two, it begins to run off. This runoff is moderated by plants when they are of sufficient size. However, as the plants grow, other factors influence efficacy of the rainfall.

Water in the garden is consumed by two processes: evaporation and transpiration. The combined processes are refereed to as evapotranspiration (EVP). Evaporation takes place from the soil surface and is strongly influenced by wind and sun. Transpiration takes place from leaf surfaces as plants breath and tends to be in the 5-8 mm per day range depending on zone. After a rainfall, evaporation starts off at a rate similar to transpiration but decreases as the soil dries out. Average EVP tends to be in the 5 mm range. Hence, one often hears that gardens require an inch of rain every 5 days (25 mm ~ 1 inch).

If a rainfall of 25 mm occurs in one hour for average soil on more or less level ground, approximately 5-8 mm might be absorbed and the rest drains away. As the leaf structure of plants expands, rain intercepted by leaves evaporates before reaching the soil surface, further reducing the amount of water provided to roots.

In a Seed Haven garden, a major portion of the rainfall will be captured and allowed to soak into the plant root zone regardless of the duration of the rain event. This is like having a mini rain barrel for each planting. The closer Seed Havens are placed together, the more complete the utilization of the rainwater. As well as slowing the flow of surface drainage, wind losses are reduced. Less watering will be required and plants will receive a healthy dose of nitrogen and oxygen.

Bait or Switch - A Pest of a Question!

Spring is arriving and as the weather turns warmer, we vegetable and herb gardeners cannot wait to start planting in the expectation of bountiful harvests. But, as the seedlings emerge, so do the crawling pests. Some of the most damaging are earwigs, slugs, pillbugs, millipedes and cutworms. There are as many home remedies for controlling this damage as there are critters. Some remedies use commonly available substances and others have to be brewed. All take time, effort and money to apply.

A class of commercial products using iron phosphate and iron phosphate EDTA as the active ingredients is gaining in popularity. Since the banning of metaldehyde and other highly toxic pesticides, many gardeners rely on these products, particularly for slug control. Some products combine Spinosad with the iron and iron chelates. Spinosad is particularly toxic to honey bees. As are the neonicotinoids that have been in the news of late. There are often usage instructions such as not applying at certain times of the day. Bees may not follow this schedule and residues on plants may be in different states of toxicity.

Every gardener has to weigh the pros, cons and recurring costs of using these products. At Seed Haven, we believe all creatures have a place and should be left alone. Why take any chances at all when there is a completely safe and economical alternative?

Here are some articles that provide information on these commercial substances.

Dog Poisonings:




Earthworm Poisonings:


Australian Article with Mode of Action for Iron Chelate products:


National Organic Standards Board review of above product: