Adventures in Rooftop Gardening

Issue 1: Tomatoes​

TL;DR: for those who don’t have the time for my poetic waxing on tomatoes.

• My name is Merry and I am an urban gardening enthusiast
• You probably want to sucker (a tomato specific pruning) your plants. I didn’t and really should have.
• Heirlooms are rad if you want to save seeds/let plants reseed year to year. If you do so with hybrids it’s an adventure.
• Keep your leaves dry and plant ventilated. Mold is gross, hurts plants, and could destroy your crop.
• Pay attention to your soil — fertilizer, calcium, nitrogen. Sounds intimidating, but in containers most of this can be balanced by what you know you’ve added and how your plants are responding. There are also soil test kits if you want to be precise.
• Support your plants with cages/stakes. Tomatoes are heavy, they need it.
• Water as evenly as possible — tomatoes can be finicky bastards about wet or dry spells. Specific soil, mulch, or drainage strategies can help.
• As with any eatin’ plants, make sure you only use soils, fertilizers, and other products that are food safe.

I suppose before I start I should introduce myself and let you know what business I have talking about container gardens, tomatoes, or even plants in general.

Oh hi, it’s my face. Taken by Baby at De-Evolutionary Photography — check them out.

I am growing a modest garden of mostly fruit, vegetables, and herbs in the middle of Seattle. My knowledge and experience comes from what I absorbed growing up, what I learn from panicked FaceTimes with my dad, and research that is mostly conducted online.

The info I present is a combination of all of the above and my experiences during this season thus far, with a bit of commentary and humor thrown in. I’m not an expert, just a they who is excited to share this passion and to encourage like-minded others to pick up a trowel and ‘dig in’ (heh heh) no matter what space they have to do it in.

The unholy overgrown tomatoes, flanked by some experimental potatoes.

The unholy overgrown tomatoes, flanked by some experimental potatoes.

My partner and I moved this year and have the good fortune of having a ~ 425sq ft roof top deck. What’s the first thing this queer, punk, anarchist wanted to do with their deck?

While tomatoes weren’t in my initial concept for the garden (which I’ll cover in a post about planning) I wanted to go over them first in this series as they grow in many climates, can be done with very limited space, and can be easily started from the seeds of tomatoes used in your kitchen if that’s your jam.

Freshly planted. Sorry for the shit picture.

Freshly planted. Sorry for the shit picture.

I opted to go with two heirloom purplish tomato plants. I prefer to grow heirlooms over hybrids for a number of reasons, chief among them being that I will reuse seeds or let them reseed their container year to year. Heirloom seeds will typically produce the same plant from seeds, whereas hybrids have a relatively high chance of reverting back to one of the parent varieties used to breed the hybrid. While the guessing game might be fun, often plants in hybrid lineages are chosen for traits other than yield and usefulness of produce- which are both things I value when growing food.

Maturing, but still manageable.

Typically when growing tomatoes you want to “sucker” them to encourage the plant to spend energy growing the actual tomatoes and not leafs and stalks. I, however, was recovering from COVID-19 when I started these mad bastards and so did not sucker them. At worst, this can prevent a plant from producing any fruit at all, but I’m not sure how common that actually is. More frequently it will reduce the size and maybe number — a trade off I was willing to live with.

Helpful?

No?

Ok, here’s a bad tutorial:

1. First and most important is deciding if you need to sucker your tomato. Apart from personal preference, the considerations to take into account are if your tomato is determinate or indeterminate, how much space you have for your plant, what your watering/moisture retention looks like, and if you feel strongly for or against steaking tomato plants.

• Determinate tomatoes have a defined size they will grow to, and time frame they will fruit during. You can get away without suckering these.
• Indeterminate tomatoes will continue growing the entire season and continue to fruit until they die. Without suckering indeterminate plants can:
• Sprawl, and take up quite a bit of space. This is particularly a problem when container gardening.
• Require extensive staking to hold up their multiple branches — especially once fruit starts growing.
• Provide more surface area and foliage density for mold to grow on — something that can happen if tomato leaves are left wet with poor ventilation.

The flip side is, of course, that intense suckering will significantly reduce the number of tomatoes your plant produce. There are always trade offs.

2. When the main stalk of your plant is 4–6in tall, start checking for small growths between branches in the stalks and places where leaves are growing out (these will likely become branches).

3. You will start to find these little nubs that almost look like teeny asparagus or a romaine heart, or if my vegetable imagery isn’t doing it, just a very small new leaf and branch. When these are found in the V made by branches/leaves we call them suckers.

4. If the sucker is small, say less than a quarter inch around, you can probably just snap it off with your fingers. Any larger than that and you should use sheers of some sort to prevent damage to the plant.

Bonus: if you are so inclined suckers can be repotted and grown into new tomato plants like other cuttings. If you want all of the plants, this article is much more succinct than I will ever be.

And that’s about it for suckering. There are better guides with pictures and videos and the lot — I highly recommend typing “suckering tomatoes” into your search engine of choice and checking out a few.

Some simply lovely leaves and flowers. I mean, just look at that curl action.

So, what have I actually done to take care of these bad boys?

• Planted in a ~2.5' radius cedar planter with a potting soil/fertilizer base and top soil mixed in to the top layer. I got organic dirt, but like — if you have access to other dirt you trust then by all means use that. Often cities will have compost/wood recycling centers where you can go buy composted soil and wood chips and all that nonsense in bulk. I have a thing about possibly exposing someone I feed to something ~dangerous~ and so have to take steps to mitigate that.
• Watered every-every other day, poured in at the base of the plants to avoid mold growth from damp leaves (tomatoes are prone to it). This one is highly dependent on the weather, as I live in western Washington state and even in summer we still get quite a significant amount of rainfall.

To check if your plants need water:

1. Check the surface. If that is cool and moist you’re good, leave them alone.
2. If the surface is dry or you are just not sure, push your finger into the soil up to about the first knuckle.

If it’s cool and moist over halfway up your finger, they can wait till tomorrow (unless this is the plant you have on life support, then maybe give it a small drink — unless it’s issue is over watering — but that’s a topic for later).

If it’s dry over halfway down your finger, probably needs a small-mid size drink. If your whole finger is dry, needs large drink.

• Small, medium, and large here are dependent on the particular plant, the size of the pot, the drainage in that pot, and if you are using mulch or something else on the surface to help retain moisture. This is something you will get the feel for. Unhelpful, I know.

My overgrown monstrosities as of early July.

• Fertilized every month with an organic fruit and nut fertilizer, about a tablespoon mixed with ~4–6 cups of soil and sprinkled on top of the existing soil layer. After you fertilize, make sure to water, as it helps pull the nutrients into the lower soil. I keep all of my fertilizer organic, and strive for organic growing practice to the best of my knowledge and ability. I use the fruit and nut fertilizer on all of my crop plants, mostly because I was already buying flower fertilizer and a food fertilizer, and getting 2–3 specialized food fertilizers seemed excessive and expensive at the time — particularly when many of the ingredients are the same. But, do what ever is best for your garden. I haven’t done a deep dive on fertilizers yet, but I’m sure y’all will hear about it when I do.
• A 1/3–1/2 dilute 2% cows milk to water solution ~ once a week, in place of watering for that day. If you don’t have 2% on hand, I’ve successfully used whole and have not had any issues thus far. If you would prefer not to use animal products there are soil supplements that can be used. I’ve even seen one argument for using dissolved tums. I haven’t looked into too many vegan alternatives, and so would for sure recommend looking more into options if you suspect your tomatoes need a calcium boost. Like watering, this is poured at the base of the tomato plants and not over the leaves. Bud end rot can be caused by a lack of calcium, and while researching a completely different plant care topic I came by this solution. This is my first year trying it, and I don’t know of anyone else who has use it, but ya gotta try something the first time to know if you’re going to do it again. I will report back and add an addendum here at the end of the season.

Four bab tomats, including a very ugly one that started life trapped between two branches. Also pictured: some buds beginning their journey to fruit, and the results of thinning the interior of the plant.

• Thinning interior leaves and non-flowered stalks. I have mentioned a few times that poorly ventilated and damp tomato leaves are prone to molding — so that is the primary drive for this. It also helps lessen the weight of the plant, which is important given my previously discussed lack of suckering.
• Light neem oil and fertilizer application, offset by two weeks from regular fertilizing. I have only applied this to the tomatoes once thus far. Plants in other portions of my deck suffered a fairly significant and utterly disturbing aphid infestation. While I have not seen any aphids or signs of aphids on the tomatoes, I am not taking any chances with those little plant leeches. I have not decided if I will be applying any more to the tomatoes specifically, as a) neem might be plant based and can be organic but it’s still a pesticide and comes with many of the risks of other pesticides, and b) it can trap nitrogen in the soil (ie. prevent denitrification). Increased and unknown amounts of nitrogen is risky for tomato soil management.

A beautiful baby tomato starting its life.

Things I should have done/need to do:

1. Sucker from a young age. The tomatoes I am growing are indeterminate, and uh, I think it shows.
2. I still need to stake them. I have gotten away with not staking this far because the branches and stalks are quite sturdy, but as the tomatoes get larger and more start to grow, the plants will need the extra support.
3. Maybe plant them further apart? These plants have been doing fine, but they are technically planted closer together than advisable based on the variety.

Until next time, break some ground, what do you have to lose?

​