I want to thank everyone who responded with advice for my last post.
Per the advice I received, I went ahead and found a 10-10-10 Scott’s fertilizer. I tried to apply it or the instructions, mixing it into the soil, and watered it in. I’m hoping for good things. One thing I’m curious about: the instructions indicate this particular product should be applied every two months, which seems like a long interval. Shouldn’t I be fertilizing more often? Did I choose the wrong kind?
Also, I finally got some straw and used it as mulch. It seems like it’s keeping the soil wetter for longer.
As for my plants: 
My potted tomato plant is taking off, more so than the ones I have in the actual bed. I installed a stake and a cage. I had primed of the first flower, but I believe it may be ready to bloom again. Do I need to keep trimming the flowers until it gets bigger?
The onions I started later are taking off, too. I planted them as far apart as my instructions suggested, but I’m wondering if they need to be thinned out. The container is small, I know, but I’m hoping it’s just deep enough for them to succeed. I do worry if I’m keeping them too wet–the container is self-watering, so I’ve watered them less, but the soil is constantly moist. Will this be a problem later on?
My herbs (rosemary, dill, African and sweet basil, and peppermint) seem to be doing well. The African basil is flowering–do I need to cut these back for any reason?
My cucumbers are growing, but slowly. Three of them are definitely bigger, though one lags behind. I’m thinking the shallow depth of my bed is coming into play here. I wonder if I should try to transfer them to a deep pit like the one tomato I have already mentioned.
The four tomato plants I have in the bed, determinate and semi-determinate, aren’t gaining a lot of height, but they do seem bushier. Again, I wonder if the shallowness of my bed is already holding them back. Stakes and cages are in place for the semi-determinate varieties, but I only have stakes for my two Roma plants.
Here’s the peppermint I was warned would take over my bed given a chance. Do I need to go ahead and transfer it to a separate area or pot now?
My loose leaf lettuce seeds have sprouted, which is cool. I’m watching them closely to see how it grows. I didn’t fertilize these plants since they’re so young for fear of hurting them.
Also, the marigold seeds I planted along the edges between the mature marigolds I planted have sprouted, as well.
These pots are on the front side of my house. The small and medium size ones have more marigolds I planted from seed. I’m wondering if they’re getting big enough that I will need to thin them out.
The big pot at the bottom has Shasta Daisies. They took a while to sprout, and are growing much more slowly than my other flowers.
I’ve got two planters with Zinnias I sewed on my porch, and they’re really doing well. I’m wondering if and when I should think these too.
I appreciate any advice you guys may have as I progress. I’m trying to learn as much as I can, and you all have been an important part of my education so far.
If everyone is okay with it, I’ll continue to post updates. Thanks for your help!
You are right to question the frequency of the 10-10-10 fertilizer. Although people refer to it as balanced fertilizer it’s actually high phosphate and high potassium. The ratio plants need to grow is 3-1-2 NPK. 10-10-10 should be used very sparingly. Usually only once in the spring at transplant. The rest of the year you should use something like 24-8-16 plus micros. The frequency depends on the species. For example peppers require 8x more fertilizer than lettuce.
The tomato - if it’s blooming again after transplant let it go. The plant will only set as much fruit as it can support.
Onions. spacing is fine. They plant them much closer commercially. Moist is not a problem, soggy is an issue.
Herbs, let them grow for a week or two then start using them. Except. The African basil - Use now. Basil booms constantly but keeps getting bigger of you cut off the blooms all summer.
Cucumbers can suffer from severe transplant shock when transplanted. Those are just coming out of it. They need heat and time to grow. Do not move them. Just be patient and in 3 weeks they will be trying to take over the bed.
Tomato beds - things grow slowly at the start, be patient. Depth is really not an issue. As long as tomatoes get enough food and water they will grow a massive plant a small pot.
Peppermint - blah blah blah it’s so invasive… BS. It spreads by runners. All it takes is a yearly pruning with a trowel and you can keep it contained anywhere. I have some mint I planted 10 years ago that takes me 10 minutes once a year to control. Leave it be and enjoy it
Marigolds - thin or don’t thin it matters not. Marigolds are very weed like and do just fine crowded.
Zinnias - that’s enough room for them. Since it’s a small pot all the plants will get enough light. Just let them go. Keep up with your watering when they get bigger however.
I work in Lowe’s Outside Garden Center. I need to print your replies here!
I get the impression the balanced fertilizer was suggested since I hadn’t included a lot of fertilizer in my soil before planting. Will this 10-10-10 be good for anything, then, if I need to go Nitrogen-heavy going forward? How soon should I apply the new fertilizer? Should I use the same stuff for all of what I’ve planted?
I’m going to let my tomatoes bloom out your instructions. Do I need to shake up each flower to encourage pollination?
I’ve been surprised by how quick my onions have been to grow. It’s likely the potting soil I used, since it’s supposed to feed for six months. When do you think I’d be safe to fertilize them?
I’m going to look up harvesting and preservation techniques for my herbs, since I don’t need a lot right now. I’m guessing drying and freezing will be what I need to do. I also don’t want to harvest in a way that’ll harm the plants. I’ll also prune the African plant’s flowers to encourage growth.
I do worry about the depth because I filled the bottom of the bed with leaves and such, so my soil depth is probably 6-8 inches, and the bed seems to have settled a lot. Should I add soil to combat the settling?
I’ll watch the peppermint and try keeping the runners in check. I’ve already noticed several runners–should I wait on trimming these?
I’m happy my flowers are okay as is. The marigolds in particular are going crazy. As I understand it, you can keep the flowers as they die, dry them, and use them to see more later. Can I just set these aside in a baggie for next year, then?
Thanks for your advice!
10-10-10 is a decent spring fertilizer for a few reasons. Cool temperatures inhibit phosphate uptake in plants. So having some extra available when the plants need it helps with early growth. Also only around 1/3 of the phosphate in the fertilizer is available immediately for the plants to use. The other 2/3rds takes some time to change formulations and become available. After the initial shot in the spring a fertilizer that matches the plants needs is a better option. 3-1-2 NPK is not high N fertilizer. It’s balanced nutrition for the plant. The rest of the summer you’ll want to use it instead of the 10-10-10. The first nutrient defiency to show will be Nitrogen. When you see the oldest leaves on the plant start to turn lime green or yellow, give it some more fertilizer.
The tomoatos will set on their own if they are outside. Either the wind or pollinators will find them.
6 month potting soil usually has manure in it that breaks down slowly over time. Just keep an eye on it it might run out of nitrogen in 3-4 months.
You can add in soil to fill it up to the top. The leaves and such compact with water and will be competing for nutrients in the soil as they breakdown.
Prune the peppermint whenever you feel like it. I only do mine yearly.
Marigolds seed: If you leave the flowers and let the seed pods mature you can reseed them. Just wait until the end of the year and there will be a ton of them all over the plant.
Does fertilizer expire? If I keep this 10-10-10 for initial planting next year, will it still likely be okay?
On the marigolds, I’ve been deadheading the flowers when they decline and saving the heads. Will the seeds not be mature if I do that?
Would just straight compost with manure be okay to add at the top? I’ll want to rake out my mulch before I add it, right?
No it doesn’t expire and it will be fine for most of a decade.
The flower heads are the plants having sex. You have to wait at least 28-50 days for the babies to be viable before you harvest the heads.
Putting that much compost and manure on top will likely be way too much fertilizer. There’s a strong possibility of burning the shit out of your plants. Use soil. You can either rake the mulch out of the way and reuse it or add new stuff on top.
Throwing out clarification since I think I was the one who threw out the even-ratio’d fert suggestion to you: your read is spot on.
The_v has a totally valid point here, but is substantially overstating the issue. Most plants do prefer an overall ratio closer to 3-1-2 over their lifetime, so if you feed them 10-10-10 endlessly, you’ll eventually get toxic build-up of phosphorus and potassium. Unless your starting soil is abnormally high in those already, that will take at least a few years to manifest, and can be easily addressed by switching to nitrogen-heavy feed until your plants take up the excess P+K.
Additionally, you don’t want to hit the plants with a higher-N 3-1-2 feed right out the gate - especially in hotter climates - since that can cause top-heavy growth with too much foliage but not a big enough root system to feed those leaves. That’s why many people add bone meal when planting or prep the bed with a higher P+K feed in the early season.
You won’t have any downside sticking with the 10-10-10 for a while; just don’t do it for years on end without getting your soil tested.
It’s a reasonable assumption but not the reasons I recommend limited use of the 10-10-10.
Phosphate - Excess phosphate is water soluable and runs off like nitrate. This causes all sorts of issues in waterways. Phosphate also has a delayed release mechanism from the fertilizer. Only 1/3 of it is immediately available. The other 2/3rd are insoluable and stays in the soil for months. It then releases over the winter and early spring and runs off into the waterways. Long before its buildup in the soil to toxic levels it’s fucked up the waterways.
Potassium - elevated levels of potassium in some species is an issue in others it’s not a problem. For example corn and other grasses will suck up extra K+ and store it. Howeve in tomatoes, peppers, potatoes etc it can inhibit the uptake of Ca+ and Mg+.
The idea that hitting plants with 3-1-2 fertilizer causes top heavy growth is myth that is passed around gardening forums and many books To put it bluntly it flat out doesn’t happen. The root/shoot ratio is quite a bit more complex than that.
Severe over-fertilization of N fertilizer is an issue for many species. This can trigger a flush of vegetative growth and delay reproductive growth. For example if you over-fertilize cucurbits it will often spontaneously abort female flowers before they open. It can also cause ammonia burns to the roots or tissues.
Not at all true for the purposes of home gardening: https://extension.missouri.edu/publications/g9181. Granular fertilizer worked into the soil and covered by mulch isn’t going anywhere.
Entirely depends on the form of phosphate. See “Table 1: Percentages of water-soluble and available phosphate in several common fertilizer source”. The runoff bit is still nonsense.
https://extension.umn.edu/phosphorus-and-potassium/understanding-phosphorus-fertilizers#materials-619210
Sure - that buildup takes a while though.
I agree that it’s more complex than that, and early 3-1-2 is in no way a catastrophic death knell, but there’s a grain of truth to it. As I think we also agree, pretty much every reputable source will tell you to prep the bed with a higher P+K feed in the early season.
A nice attempt but you’ll have to dig deeper to understand how it works.
First off this is how phosphate contaminates waterways.
The soil particles holds the phosphorus in the top few inches of the profile. Then during saturation events, it dissolves runs off with the water.
It also can leach into groundwater but it’s not as common and depends on the chemical makeup of the soil type.
https://www.usgs.gov/special-topics/water-science-school/science/phosphorus-and-water#overview
This is why phosphorus in lawn fertilizer has been banned in many states.
1/3 of phosphorus is not available to plants at application - completely missed that one.
Plants only take up the ortho-phosphate. Water soluable phosphate is usually a blend of polyphosphate (2/3rd) and ortho-phosphate (1/3). Polyphosphate is converted to ortho-phosphate via hydrolysis in water. Depending on the composition of the soil temperatere, moisture, it can take a few days or a few weeks or months to convert.
K+ interfering with the uptake of Mg+ and Ca+.
K+ , Mg+ and Ca+ compete for uptake directly with K+. Any amount of excess K+ directly competes with the uptake of Mg+ and Ca+. This is why some species just uptake extra K+ and store it in their vacuoles. If you want to cause BER in tomatoes/peppers, watermelons etc… extra K can do this the first year. These species struggle to get enough Ca to the growing point under good conditions. Anything that slows it down can cause BER.
Oh, one other thing: one of my cucumbers has a single bloom. Should I prune or leave it be? I got two pairs for pollination, but it’s on only the one that appears to have a bloom right now.
Cucumbers have two types of flowers. Male and female flowers. Male flowers have a thin stem under the flower. Female flowers have what looks like a mini-cucumber underneath of them. They only open for a few hours on one day so they never need pruning.
The blooming pattern for cucumber is referred to sex expression. There is moneocious (more males than females), predominantly female (more females than males) or gynecious (all female). This is controlled by the F-locus gene cluster.
Moneocious varieties are self fertile and only require 1 plant. These are all of the old OP types.
Predominately female varieties are all hybrids and need a moneocious pollinator (usually blended 1:10 or 1:15).
Gynecious varieties hybrids but have another cluster of genes that allow for parthenocarpy (seedless fruit). These varieties don’t need to be pollinated.
I’ve got Diva variety and another that just says “Burpless”, which I’ve found is a quality and not a variety. It appears the Diva is parthenocarphic. Not sure on the other, and that’s the one blooming. I guess I’ll find out. I’ll be on the lookout for male vs. female flowers on those.
Diva is a parthenocarpic gynecious variety. It will only produce female flowers.
Burpless = less bitter. Refers to a specific reduced bitterness gene originally from the dutch/English long cucumbers.