Best Gardening Tips is proud to present an interview with biologist and hobby gardener Carl Hawkins from Norfolk, who agreed to talk about his garden plot, general advice on gardening and tips how to improve your soil with us. We met him on a sunny day in April and started to talk about his garden.

Best-Gardening-Tips.com (BGT): Carl, the soil in your garden plot is quite loamy. What can one do with a soil like that?

Carl Hawkins: You have to mulch.

BGT:  Can you tells us some details? As far as I can see, the soil here is really clayey and heavy.

Carl: That’s nothing bad by itself.

BGT: In how far does your soil influence how you grow vegetables here?

Carl: The soil influences the water balance in the soil, you always have to keep an eye on the moisture. Most plants don’t like wet feet – we therefore dig trenches in summer, when there’s heavy rain. In so doing, water can flow of instead of staying in the soil – where it would cause mold. The other way would be to construct raised beds, where the plants are above the water line as well. However, root vegetables can get to wet even in raised beds if the soil is too heavy.

BGT: Wouldn’t it be ideal to grow everything in raised beds round here?

Carl: Of course, of course, but that depends on the materials you have at your disposal, and.. but what’s that?

Carl discovers an insect just some inches from his feet that seems to have made its way from the earth after a long winter sleep. After an elaborate explanation of the animal’s species and characteristics, we continue the interview.

BGT: Do you have a problem with slugs in your garden?

Carl: Yes, sadly. My general advice is to offer them as little habitat as possible, so no brush-wood, caves etc. There is of course the possibility of countering them with their biological enemy – ducks would be perfect. I can only recommend runner ducks to every ornithology enthusiast. They’re cute and tasty, and they eat snails.

BGT: What about planting mustard seed as a snail repellant?

Carl: I’m not sure, I haven’t tried that yet. Well, my mother always recommended lady’s mantle against snails. Quite a pretty flower, by the way.

BGT: If you encounter the problem that your vegetables simply aren’t growing well – do you conduct soil tests for nutritional value?

Carl: I think that that’s mostly not necessary. With a bit of experience it’s easy to discover how the plants are doing. For example, take a lot at that raised bed – stinging nettle, that’s always a sign for good soil!

BGT: What kinds of fertilizer do you use in your garden?

Carl: You know, I live by the sea, so seaweed is a natural choice. I made some good experience with it during the last two years, not only as a fertilizer, but also as an additive to the soil – finding the right additives is a way to truely improve your soil. As our soil here is loamy, seaweed and sand are great additives that we mix into the earth. At first I was afraid that were oversalting the soil, but it turned out all right. Seawater contains all kinds of micronutrients, so.. I want to emphasize the advantage of seaweed and similar additives to the soil’s structure in any case.

BGT: Do you think that erosion is a danger for your standard garden with only one or more harvests per year?

Carl: Not necessarily, although I would always advice fellow gardeners to use cover crop (as a method to retain nitrogen in the soil). You can use mustard plants, for example, even in late autumn – this way it will wither in winter before the bloom (mustard is an annual plant) and can then be plowed into the soil. Clover is a standard, as well.. Just recently, a neighbor advised me to plant rye, which I will try in the near future. Cover crops should always be applied in combination with compost.

BGT: Do you have a final fertilizing tip for our readers?

Carl: Horse manure. That’s simply the best fertilizer to improve your soil quality – if you can get your hands on it. The digestive system of horses is not as effective as that of, let’s say, cattle, therefore their manure contains some semi-digested plants with more nutrients and is simply a great reservoir that depletes much slower than chemical fertilizer. When chemical fertilizer washes away, it easily find its way into streams and ponds – the consequences are disastrous. In my eyes there’s no reason why gardeners have to contribute to this issue.

BGT: Thanks for your tips, Carl.

As I told you before, I’m a fan of organic gardening. Not only is fertilizer from organic sources a good additive to your soil than enhances its structure (especially for sandy soil!) but it’s also economically more viable than chemical fertilizer. Inorganic fertilizers only feed your plants and are often washed away, therefore wasting the environment.

Disadvantages of organic fertilizers are that they contain much less nutrients per weight unit (which makes them more expensive when it comes to transportation) and that they release their nutrients much slower than inorganic fertilizers.

From a chemical point of view, “organic” would be the counterpart to inorganic, which could for example be limestone. However, when I say “organic” I refer to substances not attained from chemical processing. I want to list the most important and handy forms of organic fertilizers in the following article.

Organic fertilizers

Manure: Besides being an umbrella term that also encompasses compost and so called “green manure”, manure means animal feces (from pig, cattle etc.) that may come in liquid or dried form. Manure generally improves soil structure. Its fertilizing value depends on the respective animals, f.e.:

• chicken litter is high in nitrogen and protein
• sheep manure is high in nitrogen and potash

You should, of course, consider the odor of manure from animal waste. One other important factor is its source – it may be contamined with antibiotics if the respective animals have been treated with antibiotics.

Seaweed: Seaweed supplies all three macro-nutrients (n-p-k) and amino acids; you can use seaweed as mulch or as a component of your compost heap. One potential problem is that it contains quite a lot of salt and may be harmful for worms in your compost heap. You should try (especially if you live near the coast) and observe the effects carefully. Seaweed may also be bought in processed form (dry and liquid).

Vermicompost: Vermicompost is a special form of compost that has gained popularity in recent years – it’s ordinary compost that has been thoroughly broken down by earthworms. It contains high amounts of nitrogen (which is a real bottleneck nutrient) than normal compost. You can process vermicompost in your own compost pile. See http://www.redwormcomposting.com/ for more info!

Guano: Due to its high levels of nitrogen and phosphorous, guano is a well liked organic fertilizer (plus it doesn’t smell as bad as other animal manure!). Pay attention to the fact that seabird guano is higher in nutrients than bat guano! Guano may also be applied to leaves as a fungicide.

Bloodmeal/bonemeal: Bloodmeal is high in nitrogen, bonemeal contains phosphorous in large amounts. This said, I personally don’t like to apply these both as I try to circumvent animal mass production. Ok, blood&bone-meal are only by-products, but they still add to the profits of animal farms.. You can, however, mix blood meal with water and use it as a liquid fertilizer for your plants. Bone meal is a real slow-release fertilizer that should best be mixed with the soil.

Peat: Peat (or turf) are partially decayed plants that have been trapped in moors; it may be used as fuel or by us gardeners. Peat increases soil acidity and improves its structure by storing nutrients (it does itself not contain important nutrients).

Cover crops: Cover crops are plants that are grown for some time and then mixed into the soil for structure and nutrients. Leguminous crops like peas or alfalfa are used most often, as they take nitrogen from the atmosphere and fix it into the soil, therefore guaranteeing a sustainable ecosystem. They’re also commonly used in conventional agriculture – but they’re not so convenient to use in your ordinary garden, as you would need to forgo planting of food crops for a certain time period. See my article on bio-intensive gardening for a method to circumvent this!

Kinds of fertilizer

You can decide between organic and inorganic fertilizers. First of all, inorganic fertilizers have a bad reputation with a growing number of people, but they have some advantages: As they are way cheaper than organic fertilizers, you get more bang for your buck – and they can very quickly add specific nutrients to your soil.

Organic vs. inorganic fertilizer

On the downside, inorganic fertilizers don’t really improve your soil, but simply feed your plants; they may even harm your soil as their salt content is higher. Organic fertilizers, on the other hand, release nutrients over a a period of time and will also aid the texture of your soil (especially if you use compost). So, your decision should be based on the following questions:

• What should I do if I realize that a certain nutrient is only rarely available in my soil and my plants are about to die?
  –>  Apply inorganic fertilizers that encompass the specific nutrients.
• What should I do if my soil is sandy, does only have moderate levels of nutrients and/or my plants don’t grow the way they should?
  –> Apply organic fertilizers like compost or manure.

Organic fertilizer

As you may have expected, “organic fertilizers” is a wide term. On the one hand, that are substances like compost, manure or commercial “all in one” solutions that supply all nutrients; on the other hand, there are also mediums for specific nutrients.
I would recommend to stick to the former and only apply specific nutrients if your soil are lacking only this nutrient. The following list will give you hints about the most common organic fertilizers:

• Compost: Nutrient levels of compost are not as high as those of other fertilizers, but it’s for free (if you’re composting your garden waste) and adds good organic matter to your soil
• Manure: Has higher levels of nutrients – especially nitrogen – than compost, but you will have to get it composted before applying (otherwise its ammonia levels are too high; also, your neighbors will hate you for the smell ).
  You can ask a local farmer about acquiring manure, but apply it with care (and enough time between application and harvest, if you’re having a vegetable garden).
• Important: As manure supplies high quantities of nitrogen, application in high amounts will cause foliage and weed growth!!
• Peat moss, grass clippings and cover crops (grown on unused land and later cut and tilled into the soil) will have the same effect as compost – cover crops will also help you to suppress the growth of weeds.
• Other fertilizers supply primarily one kind of nutrient to your soil: Fish emulsion (nitrogen), bone meal and seabird guano (phosphorous) and wood ashes (potassium).
  I especially found that alfalfa meal is a good plant-based supplier of nitrogen, potassium and trace minerals.

In the end, all soil will benefit from the addition of organic matter in appropriate measure. Inorganic fertilizers should only be a supplement if “normal” fertilizing hasn’t been sufficient or isn’t fast enough.

I hope youenjoyed this article – to me it was fun writing it as it helped me to put my experience together in a short, clearly-arranged way. See you next time!