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Originally Posted by agavegreg
Check the older threads, I believe there is one on fertilizers.
What I want to know is- who fertilizes their succulents and what do you use??? Looking at some of my specimens, Im convinced they could do with some very dilute manure or potash, as most other plant groups benefit from these two. Does anyone use a commercial fert? Anyone killed anything with it yet ?  |
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Greg - Start a poll!
We do not subscribe to the theory of adding fertilizers to our mixes (except the starter fertlizers already in the bulk mixes from our supplier) and do not fertilize any of our cacti or succulents. Having grown over 1 million dudleya seedlings during the past 23 years, we just have not seen the need. Those customers of ours whom dose the heck out of their plants regret it later as their dudleyas become Dudleya monstrosa and morphologically have lost all association with the parent plant stock. They also are more frequently prone to disease, turgor pressure induced leaf damage, fungal and bacterial infections. Leaf growth is a cube function and not a width and length function. To much fert and water and the leaves outgrow their waxy cuticles and voila, infections. My opinion anyways. Paul Agner prepared a great article on saxicolous plants and their very small required soil quantities. There is a limited nutrient availability for these types of plants, yet they thrive. Trying to recreate the exact soil mix for the plants in question ignores the fact that the environmental condition including photoperiod, water relations, mycorrhizial associations, etc., are not being duplicated. Some myths die hard. Putting pot shards in the bottom of the pot to increase drainage is a good one. The soil above the rock/pot shard interface must become supersaturated prior to transfer of water to the next media and thus, results in stagnation zones of water at this interface. The elemental matching we all strive for has also been disproven in that endemics to specific soil types do not require that soil, they just can survive in that soil. Serpentine plants are a good example. Many plants cannot handle the high nickel and arsenicals in the soil and die when exposed to these types of substrates where others can survive and thrive, but through some adaptation, are out-competed in adjacent soil mixes and cannot thrive and die out. My limestone dudleyas are a good example. I do not grow them in basic soil and they have survived for 10+ years. I am also confident that my Opuntia echios, O. megasperma and O. galapegia are not on the same complex soil matrices that are found on their respective native islands.
Look at the UC Soil mixes and John Innes soil mixes. An attempt to standardize for the industry and still viable today. I am amazed when I purchase the odd plant from the big-box store and find a Euphorbia growing in almost pure peat, and wet gooey soils, and thriving. Same with the plants I get in from the TC people that are using pure peat and lots of liquid ferts and Banrot. Standardization for ones collection is the best basis as it will allow a more normalized watering schedule - my humble opinion. If everything has the same drying rate, then it can be more readily predicted when plants might need to be watered. Remember the days when people thought that cacti grew in pure sand, bought a bag of play sand and watched as their plants slowly perished.
The same goes for the water acidification theory recently being resurrected by some. Buxbaum's theory is dated and even after all these years, is not a standard reference for those cultivating cacti. The hydroponics people and universities have performed countless studies on nutrient uptake based on pH and found that the data supports a more neutral to only slightly acidic water. Some elements do have higher uptake at lower pH, but what compromises are made with respect to the other natural ratios now being out of proportion. The nitrogen and lightning relations are overstated as well. My atmospheric chemistry research and reference materials state that only 5% of the available nitrogen is contributed by lightning. That is a statistical outlier (a number and not a meaningful data set).
Start a poll and let's see what the other members do.