I am glad you asked this question. Unfortunately, I don't have the answer. However I've had a strange thing happen here in my yard and would be interested in getting some opinions as to what might be going on. We have a small pond on our property that is filled with submerged aquatic plants and algae. Most is made up of elodea and string algae. I routinely use a rake to remove excess from the pond and make large piles around the edge. After they dry a bit they are a lot lighter to move around and I have been placing them around the bases of some of my established trees as a mulch. OR I have pulverized to a fine dust and sprinkled in beds. I started doing this last spring and have noticed that a plum tree that I did quite often last year is dead now and a bed containing a mix of thyme and oregano has not come back. I cannot rule out other causes at this point so I haven't given it much thought, but it did cross my mind that the pond plants may have played a role. So if anyone else has experience in this area I am all ears. And yes, we all know that it would be better to compost it first, but I am a huge advocate of passive composting.

I talked to a supplier and was told that the liquid will mold over time and keeping it cool will help slow this down. I live in a hot climate and buy the powder so I just mix what I will use. This also lowers the shipping cost. The powder must be kept dry or it will turn to paste which is still usable, but messy. I'll repack the powder into smaller airtight container to try and keep it dry. I was given a gal, not sure what brand, of the liquid as a gift and used it for several years with no noticable mold problems, but it did thicken up. Think it is really a matter of availabitity, cost, and personal preference. Kelp is sold as a meal or as an extract of the meal in liquid or powder form and provides some 60 trace elements and growth promoting hormones and enzymes. The meal is a slow release and the sprays and drenches are more quickly absorbed. I like to have both methods available. Hope that helps.

from what i have read seaweed or kelp meal can not be substituted by anything. the whole purpose is to provide trace nutrients that could be lacking. some of these elements are not even needed by plants such as iodine yet are essential to animal health so it is indirect consumption first getting the nutrients into the plants then eating the plants. arsenic is another essential to animal life yet totally unneccesary to plants as well as we currently know. sea products tend to contain almost every mineral in trace amounts so fish meal or emulsion could possibly contain some or all of the things kelp or seaweed provides. Kelp meal is recomended at 1 cup per 100 square feet annualy in a book gardining for maximum nutrition so it is used in very minute qty. I can't help but wonder why bother with secondary igestion why not just consume minute qty of the meal directly in say stews soups gravies etc. Part of the logic no doubt is that the application to the soil also allows for any trace elements lacking in your local ecosystem and thus not present in localy produced organic debris. Importing components of the compost heap from distant sources may also have some advantagous effects such as using stable cleanings that have sawdust from nonlocal trees and feed comprised of products from several regions. so there is no substitute for seaweed or kelp meal to the best of my knowledge. I have yet to find a reasonable priced source. Anyone living near the coast could simply harvest rinse the salt and add the seaweed or kelp to the compost heap those of us inland must import to obtain it and prices seem to be way to high for what it is. Anyone knowing of low cost commodity co-op type suplies please post them.

Kristine and lkaye, thanks for the tips! I have never sprayed something on any plants foliage......so reading about how people do that interested me, but still a bit nervous. This is my first year with a decent amount of roses in the ground instead of one or two in a pot that I did nothing for in the past. Maybe since I used the rosetone 2 weeks ago around each plant I'll wait another week or two before trying to add the fish+kelp drench on each plant. Do either of you know if it can really hurt the plants after using Rosetone? These are all new in the ground, I planted them probably a month 1/2 ago or little less for some (I planted 30 something). I've read organics tend to burn plants less, but I still want to be cautious about damaging any. Thanks again!