Garden Soil Preparation – Using Fertilizers And Mulch

61 Comments

1. Again Thank You and Very Well done. Barry.

   1. Why do my root vegetables grow large tops and nothing or very small vegetables

      1. It’s most likely a nutritional imbalance in the soil. I would find a good soil lab and work with them to get your soil balanced.

2. Great job! Does it matter what kind of straw I use?

   1. I definitely prefer straw from an organic farm (conventionally-grown hay/straw may have pesticide residues), but I don’t get too hung up on the crop it’s from. It’s a bonus if it’s from a legume like alfalfa, but I’ll take rye, wheat, buckwheat, whatever.

3. With a lot of straw, doesn’t that become a home for insects and rodents that may eat your garden plants?

   1. Hi David, it’s a home for good insects and “bad” insects, but the straw isn’t the reason why they eat the plants. That’s a plant health issue ( https://www.smilinggardener.com/lessons/non-toxic-pest-control/ ). But in terms of rodents, you’re right, that can be the case, which is why we don’t want to apply any mulch too thick around tree trunks and other plants that they like to eat.

4. can i use pine straw?

   1. Funny, I just happened to answer this question somewhere else yesterday: I’m not too knowledgeable about the chemical makeup of pine needles. I wouldn’t put 2-4 inches in a food garden, but I would definitely do it in a garden with plants that would be used to that kind of mulch. My preference would be to mix it with leaves for mixed ornamental gardens.

5. When you “double dig” does that simply mean that you are going over the bed two times, working the compost etc into the soil, with the 2nd time being deeper than the first?Also, when you mulch before planting I am assuming you are planting young plants (not starting seeds in ground)?How long once you’ve prepared the soil this way do you typically wait until you actually plant? (Is there a best/maximum timeframe?)

   1. Hi Heather, double digging is when you dig a trench, remove the soil, then dig in that trench deeper to loosen the soil below. Do that all along the bed, each time bringing the soil from the new trench into the last trench. Eventually you have a bed that’s been loosened very deeply.I can have a very thin mulch and start seeds in the ground, but if it’s a thick sheet mulch like I did this year, I only plant young plants.If possible, I do my preparation 2 or more weeks before planting to give the soil and compost some time to get acclimated, but you can plant the same day as I did here.

6. I’m having trouble finding “calcitic lime” – can anyone tell me what name it might be under at the garden supply store? They have agricultural lime and dolmite, that seems to be about it.

   1. It can sometimes be tough to find. It might be called calcium carbonate or marking lime. If you can’t find it, gypsum would be an okay second choice, but stay away from the dolomite and ag lime.

   2. I frequently find “calcitic lime” called garden lime. If you have done a soil test and have a Mg deficiency you could use dolomiite lime. Don’t use dolomite unless you verify a magnesium deficiency though, excess magnesium can make soil compact and get hard.

7. Ohio State University did a study on mulches and they concluded that the top three, when it comes to controlling weeds and maintaining moisture (etc) were a) compost (a layer on top), then b) Fall leaves, and finally c) straw.  They highly recommended against nitrogen-hogging mulches such as wood chips.  Comments?  Have you tried compost itself as a mulch?  This was new to me…

   1. I’m a huge fan of leaves and straw, but in my experience, compost is not a weed control at all, so I’m not sure what they’re getting at. It is true that establishing a healthy soil food web can discourage some weeds, but compost itself just gives plants (which weeds are) a nice growing medium.I generally agree on the wood chips. A thin layer could be used if you had a good humus content already, but I prefer the more natural mulches of leaves and straw.

8. Phil, I totally get your point about leaf mulch. But one issue about using leaf mulch in a tropical climate like where I am gardening, is that it tends to attract mosquitoes. I was also told that piling up the leaf mulch too near the plant can encourage fungal diseases. Would you know of a practical way to use leaf mulch so that it doesn’t provide a haven for mosquitoes to breed? I’d really like to know what you think.

   1. Hi Ramani, good question, and I can’t really give a good, thorough answer. I have no experience in the tropics or with the tropical diseases mosquitoes carry. On the one hand, we can’t go creating a totally artificial (unmulched) landscape just because we want to discourage mosquitoes, because we need to protect the soil and we need to work with nature. On the other hand, I understand that providing a home for mosquitoes can be a dangerous proposition.My opinion would be to go with a thin mulch of some kind of organic material to nourish the soil, and find multiple ways to deal with mosquitoes. Where I live, setting up habitat for bats is one option, because they eat a lot of mosquitoes. A multi-faceted approach is probably necessary. Also, some leaves (Gliricidia sepium and Azadirachta indica) may actually repel mosquitoes.So there are a couple of ideas, but as I say, I think several methods to reduce mosquitoes are in order.

      1. I’m a big supporter of multi-faceted approaches.  Another one might be to run the leaves through a shredding/mulching machine, if you have access to one.  That would chop the leaves up into much smaller pieces so that little pools of water couldn’t collect in them.  It would also speed up the decomposition process. 

9. Hi, I am from the Hudson Valley in New York and live in a deciduous forest environment with around 6 hours of strong light in afternoon on my veggie garden.  it is a very organically  shaped 500 sq foot garden with  paths and terraces due to hill, so the beds are  without any straight lines. In terms of design I make sure that there are strategically placed flat stones throughout the garden, so I never have to walk on the soil to harvest or weed. Since we have many leaves in the Fall (mostly Oak and Maple), I grind them each Fall ,cover the flower and vegetable gardens when I ‘put them to bed’ for the Winter and  put a tarp over the excess for spring planting and or expansion.For the first time this year I am using EM-1 on the soil and starting fertilizing with fish and kelp food.  Confusion about the lime question without having first tested the soil means I have added none, though acid rain and oak leaves are a part of all the compost available here and the source I have has a reputation of being a little acid.  would a light dusting on the surface around the plants and stirred up before putting ground leaf mulch back in place be OK?  And also since I have very young plants and seeds in now when do I start with foliar fertilizing?I appreciate your practical and informative site as well as the Academy.

   1. A very light dusting of lime is okay. I usually say just 5 pounds per 1000 square feet. Oak leaves don’t necessarily make soil acidic. The reason you don’t want to add much without a soil test is because it’s possible that you could have adequate calcium and still have acidic soil. Now is a great time to start foliar feeding.

10. Just an addition:  I am growing with densely packed companion planting different species with lots of Marigolds, Basil, catnip and sage (Harvested for Pesto along with my Garlic), utilizing shady corners for Bok choi and other shade tolerant plants. I have noticed insects are going after my new Collards, would a dose of EM help to stop this by giving the plant an edge and or fertilizing foliar?.

    1. Yes, EM is not a pesticide, but exactly like you said, it often gives plants the health they need to discourage insects. I would definitely try it before anything else.

11. MERGFrom sth.australia i like useing sugercane or pea straw mulch that has been choped much easyer and neater to use;

    1. Sounds great to me.

12. I read a review of rock dust that said it contained lead. will the lead be absorbed by my fruits and veggies?  Thank you

    1. Hi Kathy, a little bit of lead is perfectly natural in soil and rock dust. There may be some rock dusts that have too much, but I don’t know how much is too much. I would like to learn more about that.

13. What is EM and would it help for flies? When I plant in spring my young pepper and eggplants get attacked by flies and make lots of holes. I have tried egg shells and coffe grounds and hair but plants still get eaten. Any suggestions.

    1. Hi Peter, when you improve the health of your soil and plants, the flies will go away. EM can definitely be a big help with that.

14. I used to use straw for my mulch but I realized straw has little nutrional value, so I switched to hay with it’s hay seeds and all. Cows grow very large and produces milk eating hay where it won’t prosper eating straw. When I get weeds popping up from the seeds I take it as a sign I need more hay and shake some more around. My garden is weed free as I write this and I don’t seem to ever have to water once my plants get established. Hay is more readily available In this area then straw and I know the fields it comes from. Do you foresee a problem using it this way?

    1. Hi Sharon, I think you’re just fine. You are increasing the seed bank of your soil, so if for some reason you ever stop mulching, the beds may get covered in weeds, but it sounds like it’s working out great for you right now.

15. You are using bale, can I use bale from rice, Philippines is my country, we’ve plenty of rice fields.

    1. Absolutely, rice stems make a wonderful mulch.

16. it is a good idea to add lime if you live in a alkaline environment? i live in southern california and i’ve heard not to add lime because it will raise the pH too high. What do you recommend?

    1. It’s possible to have an alkaline soil that is low in calcium and/or magnesium, so in that case, it would make sense to add the appropriate type of lime to your soil. The only way to really know is a good soil test that measures cations like calcium and magnesium.

17. If these mulches are preventing weeds from growing, would they not also prevent the seeds we want to grow from coming up? Should I pull the mulch away where I have planted seed?

    1. Yes, pull the mulch aside until the seedlings are up and sturdy, and then you can bring the mulch back around if there’s room.

18. where would I find straw for mulching?

    1. From a farmer or craigslist/classifieds or a store that sells feed/bedding for horses.

19. Dear friend,Mine is a small 12′ X 12′ garden in a townhouse community; I have evergreens (Azaleas, rhodo, Boxwood etc); I have purchased the Lime & the Rock Dust;To apply these, for improving my soil, do I need to do digging or can I just apply on the surface, water it down, & hope that it will go down into the soil.ThanksBalram

    1. I like to very lightly incorporate them into the top inch of soil if possible, with a rake or garden fork.

20. Where can you buy rock dust?

    1. Local specialty fertilizer supply stores or occasionally garden centers. Or you can go to a quarry, but you need to test that dust out to make sure it’s useful.

21. Have you ever used crushed egg shells for a source of calcium for the garden? My grandmother used to put a tablespoon of crushed eggshells for each tomato plant she put into the garden. Is this effective?

    1. Ya, it’s obviously not a lot of calcium, but it’s a nice whole food source for sure.

22. Hi Phil, is rock dust the same as Azomite? the instructions for azomite are 2lbs per 10 square feet…seems like a lot. Thanks!

    1. Yes Azomite is a brand name for Rock dust. Another brand is also called Gaia Green Glacial Rock Dust.

    2. sewpretty13 is right – azomite is a brand. 2lbs per 10 square feet is a good application rate, but if money is an issue, you can definitely use much less (e.g. 75% less) and still get benefits.

23. How thick is your mulch?My allotment neighbours complained that my straw mulch attracted mice. What would you say?Also, I have compared putting a straw mulch on with adding compost in the summer around plants without digging it in. I found that the compost was much easier to work with, whereas the straw held more slugs! Plus I had to pay for the straw but the compost is free.Can you use grass clippings as mulch? How thick?Would you put mulch on in the spring or wait till early summer?

    1. My mulch is 1-3 inches thick depending on what I’m growing – bigger plants can take more mulch.Yes, it can be a good place for mice and rodents. If your allotment had a cat, the problem would be solved. The problem with that single-cause, single-effect thinking is that if we remove the mulch just because it attracts mice, we’re not considering the fact that removing the much creates an environment that is even more unnatural for the plants, meaning WE have to take on the task of weeding, more watering, more fertilizing, more compost, etc. It still may make sense to remove the mulch (even if just temporarily) in order to dissuade mice, but it should be done within the context of the bigger picture.Yes, straw holds more slugs, too. The solution there is to have a garden in full, hot sun where slugs won’t want to spend much time, and don’t overwater the garden (or water too frequently), and grow healthy plants that the slugs won’t want to eat, and house a diversity of animals to eat the slugs. Compost has a lot of benefits, but doesn’t usually control weeds very well or provide some of the other benefits of mulch. I prefer to use both, but you’ll have to decide what works best in your situation.Grass clippings can be used in tiny amounts in the garden, but they can’t be used alone as a mulch because soon as you make it thick enough to be a good mulch (whatever that may be), you’ll find they may get anaerobic and smelly and therefore detrimental to the garden. In small doses they’re fine.I often wait to top up my mulch until later on in the spring when my seeds have come up strong and when the soil is warmer.Hope that helps!

24. Loving the videos and info. Finally learnt what double digging is, for some reason we don’t seem to do that much in the gardening world here in Australia. Depending on how long I think I am going to live in a place and how much time I have and the quality of the soil, I have a very lazy way of starting and improving the soil in a potential new garden bed. It simply requires lots of patience and time to let nature do it’s thing. What I am lucky in, is that living in a sub-tropical area of Oz, things are growing all the time which allows me to do this and decomposing happens all year round. I work out the garden bed area then I simply pile grass clippings, prunings, leaves, shredded paper anything that was once living onto the area and I just keep piling it on and I don’t touch it, no turning, nothing. When I first start the piles I let them sit for a month then I will put some worms on the out edge and I let them do all the digging and soil breakup for me. When I have the time to get to that area to finally plant I go back and scrape off everything that hasn’t decomposed. Do my tests to see what nutrients are required and away I go. I did this in an area where you literally could not put a shovel into the ground it required a crow bar to break it up and it was basically clay (so I added the odd handful of gypsum to the pile) obviously there were no worms or burrowing insect life in the ground. It took 2 years before I got to that area (it was a very large block) but when I finally went back I could dig the shovel all the way in to the top edge and the soil was teaming with worms. It was a delight to work and the old farmer next door was shocked as he told me I would never be able to get that piece of ground to be viable. It’s now filled with trees and shrubs that are shallow rooting and can handle a deeper clay and rock base.

    1. Beauty! That would be your basic sheet mulching technique, which I often teach is being kind of the opposite approach to double digging. Both have their place for sure, and I certainly use them both. Thanks for sharing in such detail 🙂

25. good video, but, what has happened to your recommendation of sea mineral or ocean water fertilizations? i watched one of your youtube clips and you were so adamant that the use of ocean water was so beneficial to the soil as it contained so many trace minerals etc?

    1. Yes, ocean water is amazing, and they do use it directly on the soil, but I think of it more as a foliar fertilizer than a long terms oil improver – it’s great to spray it on the soil too, though. I use it a few times a year in my garden on plants and soil.

26. Wowow! Get better understanding now about Calcitic Lime and Rock dust. What is the difference between Calcitic Lime against all other lime? Could I differentiate them by physical appearances? Rock dust getting from a quarry, is it a kind of silt accumulation wherein I can collect? Thanks so much Phil.

27. First, let me thank you for ‘smiling gardner’ I hope i havent missed too much – talking of which I have for several years used unglazed cardboard torn up to shape and size for mulches – strawberry for example, or just dig in the soil for a bit more water retention in my sandy soil, Is this ok?

    1. Using cardboard as a mulch to blok weeds is okay. As for digging it into the soil for water retention, that could work – just make sure it doesn’t create a layer of cardboard buried in the sand because it might stop water from infiltrating deeper.

28. What about using sugarcane residue (what remains after extracting the sugarcane juice) for mulching? Is it at as good as the dry leaves?

    1. Yes, sugarcane works too.

29. Will be moving to Ontario early 2016 South of Ottawa; Carlton Place, Renfrew or Kemptville area. I will be taking 1/4 to 1 acre of ruff scrub/treed land (no field or open pasture) with HEAVY clay soil. My question would be how does one prepare the acreage or the proper process for a vegetable garden? Mainly the concern is the heavy clay soil for the best way to change the texture towards a loam clay.

    1. Hi Walt, you can’t really change the texture (the technical definition of ‘texture’ is the mixture of sand, silt and clay, and you can’t really bring sand into clay – it’s very expensive and causes other problems). But you can change the ‘structure’ by bringing in organic matter in the form of compost, manure, cover crops and other organic debris. And that’s where most gardeners stop, but the other important side of the picture is balancing the nutrition in the soil by sending a soil sample to a good, organic soil lab and then using fertilizers based on those results. It’s too complicated to explain the whole process here in a comment, but I talk about it sometimes on this site, and it’s a main focus of my online gardening course.

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