Thursday, October 14, 2010

Materials and Techniques: Watering and Tracking 800+ Plants

In the comments to Tuesday's post, a few people asked about my system for watering and tracking all 875 of my plants.1 Bits and pieces of this have been referred to elsewhere, but I haven't put it all together in one spot before. It was difficult to organize this in a coherent way, so I apologize in advance if it's confusing. But hey. [Some of] You asked.

I have 875ish plants at the moment. Most of them (413) live in the basement, but there are also plants in the living room (86), my office (77), the husband's office (16), and the plant room (276), plus a handful of plants (7) have not yet settled into a permanent spot. There are also a number of cuttings, seedlings, and the like that I have not yet declared to be official plants, but which still require care to some degree or another.2

This is way, way too many plants to water all in a single day. It's too many plants to water in three or four days, even. I could do that when we still lived in the apartment, if I really pushed myself, but that was 500 plants ago. So, I have had to divide it up and do them one set at a time. Initially, I was still trying to push myself really hard to get as many watered in a day as possible, but I've found it works a lot better if I spread the task out as much as I can. So now, the idealized schedule goes like this:

Day 1: first section of the basement (check and/or water 153 plants)
Day 2: second section of the basement (182 plants)3
Day 3: third section of the basement (75 plants)
Day 4: outside plants, if any, plus the first section of the living room (40 plants)
Day 5: second section of the living room (48 plants)
Day 6: offices (93 plants)
Day 7: first section of the plant room (81 plants)
Day 8: second section of the plant room (99 plants)
Day 9: third section of the plant room (62 plants)
Day 10: fourth section of the plant room (42 plants)
Day 11: free day; emergency watering situations only
Day 12: free day; emergency watering situations only

And then it starts back over again in the basement.

Part of the second section of the basement, as well as the entire third section, with annotations that might or might not be legible once Blogger shrinks the photo down. Includes a few plants that aren't officially plants yet.

I say it's the idealized schedule because I strongly doubt that any actual watering cycle has gone this way. I fairly regularly have days when I wake up and think, oh my god I cannot bear the idea of watering anything today, so then I don't, or some days, I know I have the opportunity to go somewhere the following day, so I try to do two days' worth of watering at once, meaning that some stuff gets done early. Occasionally I check a few plants and everything still feels really wet, so I skip it for a day. And so on.

So the overall cycle takes between 12-16 days, usually, depending on how I'm feeling and what options I have for better entertainment.

The majority of plants wind up getting watered, then, once every 12-16 days. A smaller group only get watered every other round, so for them it's every 24-32 days. A handful get watered even less often than that.

And then there are those for which water every 12-16 days is not often enough. Various things can happen to them. Sometimes they just die outright, and that's that. Sometimes I move them to the basement, which is cooler and more humid, where they use water more slowly and might be able to fit the 12-16 day cycle. Sometimes I'll move them to a larger pot, so they'll dry out more slowly. Some eventually learn to live with less frequent watering than they'd prefer. And a few get special treatment.

"Special treatment," in this case, means that I go down to the basement every morning and check to see if anybody's having a watering emergency. A lot of the plants down there are, as a consequence, sort of on their own schedules.

So then how do I keep track of what's been watered, and how long ago, and all that?


I maintain two large spreadsheets for the plant collection. One (the "census" spreadsheet) lists all the official plants by family, genus, species, variety, date of acquisition and source of acquisition. This is not particularly relevant to the watering, but it does provide something to check against, so I know that everything that's supposed to be on the watering spreadsheet is there. The census spreadsheet is also useful for making graphs, like for example this one, which breaks down the plant collection by family:

The top five, in case you don't want to open the picture to look, are:
  1. Araceae (aroid family),
  2. Asphodelaceae,5
  3. Cactaceae (cactus family),
  4. Bromeliaceae (bromeliad family), and
  5. Lamiaceae (mint family).
The other spreadsheet is more strictly for watering purposes, and contains most of the same information, plus the date of the last watering, the location of the plant (living room, basement, plant room, etc.) and a series of columns that cover the last four months. To find out whether I watered a plant on a particular day, I find the horizontal row for the plant in question, and follow it over to the vertical column for the date in question, and look to see whether I entered y[es], n[o], or r[epotted],6 which tells me whether I watered, didn't water, or repotted that particular plant on that particular day. Then the spreadsheet counts the number of n's and y's and r's, figures out how often I'm watering the plant on average, adds that number of days to the date of the last watering, and comes up with a guess as to when it thinks the next watering is likely to be.

Usual size. The left pie graph shows how far along in the watering I am; the right pie graph shows how many plants are in which rooms. The first date, on the far left, is the date of most recent watering. The second date, to its right, is the computer's guess about when it will need watering next. Then there are four columns for identifying the species and variety of plant, the date acquired, and a (partly-redacted) column for where the plants were acquired. The bright-green row of "2"s indicates that all the plants in these rows have been checked. The sky-blue, green, and orange on the far right indicate the days on which the plants here were not-watered, watered, and repotted, respectively.

This is the shrunk-down version of the same spreadsheet, so you can see the regularity with which watering happens. (Oldest dates are on the right, newest on the left, the opposite of what you'd expect it to be.) Again, blue means not-watered, green means watered, and orange means repotted. I have conditional formatting set up for those cells, so all I have to do is type n, y, or r and the cell colors itself. The dark purple is for plants which "didn't exist" yet on those dates: they hadn't been made official, or hadn't been purchased yet, or whatever. The grayish cells at the far right of this image are for indicating what room the plant is in and calculating the average watering interval.

Now. I don't automatically take the computer's recommendation into consideration, but it's useful sometimes, because it lets me know if something is staying wetter longer than it used to (in which case it might have mealybugs, or it might be in a spot that's too cold), or drying out too quickly (in which case it might be in too hot of a spot, or need to be repotted). It's also useful as a tiebreaker, in those cases where I'm not sure about whether something is dry enough to water yet: if the computer says something should have been watered three days ago, I'll usually go ahead and water it again even if it still feels kind of wet, and if it says it's not due for another week, I'll usually let it sit.

But so anyway. On watering days, I go through whatever the room for the day happens to be, and check the various flats and pots to see if they're dry. Anything that is dry is taken to the plant room in a large, sturdy, waxed cardboard box, watered in the plant-room shower, allowed to drain, and returned to its original spot. Then at some point, I go down the list of plants typing Y, N, or R as I go, update the last-watering-date column and changing the number in one of the columns from 0 to 2, indicating to myself that I don't need to look at that plant again. Then it's time to pick up a new batch of plants.

The cardboard box (actually a box inside a box, if you look closely -- I need the added strength or the cardboard starts to bulge outward, and then plants fall over when I'm moving them) here is from the ex-job. A lot of the plants that were shipped in boxes had one of these at the bottom of the box, for reasons I never completely understood. But they're very handy plant-transporters. I can fit about one shelf's worth of plants in the box at a time (maybe 6 or 7 6-inch plants, or two standard-sized flats), which doesn't sound like a lot for one trip, but it's better than two plants, which is all I could manage with just my hands, and a surprisingly large amount of the watering process is just walking plants back and forth, so anything that cuts down on the walking is a big time-saver.

Also once a week or so, I have to cut some of the columns off the right end of the four-months stuff and paste them back in at the left, and clear out the data in those columns, because there's only room for four months' worth of information, the way I've set the sheet up. There's a lot of stuff wrong with the way the spreadsheet is constructed -- I scroll around the document a lot more than I should have to -- but now I'm used to compensating for it.

It sounds complicated and time-consuming, I know. It's actually only complicated, if that helps. I mean, dealing with the watering spreadsheet does take time, but it's made me a very fast cut-and-paster, and I have the spreadsheet sorted by room, so I only have to scroll through the plants in the room(s) I'm watering on that day, not the full list.

There's also a certain amount of paperwork involved, any time I buy a new plant or a plant dies, which is most of the reason why I have so much plant material in the house that I'm not counting officially yet. (Unofficial plants get dealt with on the same schedule as official ones, though quite a few of them are in enclosed or mostly-enclosed containers and consequently don't actually need anything from me beyond occasional checks to make sure they're alive.)

And when I have to rearrange the plants in a way that involves plants moving from room to room, my entire world falls completely the fuck apart for a number of days.7 But mostly, imperfect though it is, this system suits my purposes.

So that's how I keep up with over 800 plants. The more interesting question, of course, is why I have over 800 plants to keep up with. That's a much tougher question to answer.


1 That number has changed eleven times in the last month, though, from a low of 864 to a high of 877, and in fact actually changed once while I was writing this post, so the numbers in this post should be understood as approximately correct, not absolutely correct.
2 Why not just count everything, you may be asking. The answer to this is complicated, but some of the factors include: 1) Counting cuttings before they've taken is a lot of unnecessary work for me; as you'll see, there's some paperwork involved anytime a plant is purchased, made official, or dies, so it saves me a certain amount of time and effort if I don't have to count a bunch of cuttings on Sunday if I expect half of them will die by Wednesday. 2) The main purpose served by having an official count of the plants is that it helps me keep track of what's what during watering. A plant rooting in a glass of water, or a set of Abutilon seeds I'm trying to sprout under a plastic dome in the basement, still need to be watched, granted, but they don't need to be checked in the same way, and including them in the official count just means I have one more thing to check off, which takes more time.
Therefore, plants only get counted when they're in a pot, require regular watering, and are expected to survive for a reasonably long period of time. Presently, I'm not counting:
• a Saxifraga stolonifera offset that's only barely hanging on,
• 9 Abutilon seedlings,
• a pot of Cissus quadrangularis cuttings which may or may not root,
• maybe 15 Zamioculcas zamiifolia leaflets, roughly 5 of which have sprouted a first leaf,
• a plastic clamshell container containing a layer of Cyrtomium falcatum slime and maybe the bare beginnings of some first fronds,
• another clamshell containing some Episcia 'Coco' leaves (which are rooting abundantly but don't seem inclined to sprout more leaves, so far),
• two Dieffenbachia stems that I'm rooting in water ('Camouflage' and 'Pacific Rim'),
• another clamshell containing Begonia 'Tiger Kitten' leaf sections and a leaf of Hoya polyneura that accidentally got knocked off while watering,
• water-rooting Solenostemon scutellarioides 'Glennis' and 'Splish Splash' (2 stems of each?),
• water-rooting Salvia elegans (3 or 4),
• water-rooting Plectranthus amboinicus (2),
• three water-rooting (?) Philodendron gloriosum stems,
• two Philodendron gloriosum stems I'm trying to root in vermiculite,
• two Hibiscus plants I took off of the official list when I decided I didn't want to go to the hassle of trying to overwinter them, but then brought in anyway before it froze here because I thought maybe I wanted to try to overwinter them after all,
• a tray of about 25 Plectranthus verticillatus cuttings that I totally don't need, but that I started and can't bring myself to kill, even though they take up a lot of room,
• about 30 Crassula ovata leaves in a tray that I'm trying to grow into new plants (only two have done anything visible so far, though),
• 9 Cryptanthus offsets that I stuck in a couple 6-packs, where they rooted, which I totally intend to put into their own pots at some point but I haven't done it yet, and
• 5 Sempervivum offsets that I was saving through last winter to plant outside but never got around to planting, which I don't even like anymore but can't bring myself to throw away.
3 This is less impressive than it looks; most of the plants in question here are on flats, that I water or don't-water all at once. Plus the basement is exceptional anyway, for reasons I'll get to.
5 Asphodelaceae is not recognized as a legitimate family by some taxonomists, but the taxonomists that don't recognize it recognize the Xanthorrhoeaceae instead. The plants I have that I list as Asphodelaceae are all in the same family either way, whether you call it Asphodelaceae or Xanthorrhoeaceae, and it's not that important for my purposes which it "really" is.
6 Repotted counts the same as a yes, because I almost always water plants in after repotting. On the rare occasions when I don't water the plant in, I still record it as though I did: the system is kind of inherently imprecise.
7 This is going to be happening relatively soon, I think, because the plant room gets uncomfortably cold during the winter despite our best efforts to insulate and heat it, so the more cold-sensitive plants will need to go to the basement, and the more cold-tolerant plants will go to the plant room. It promises to be a huge mess, spreadsheet-wise.


Plowing Through Life (Martha) said...

Seems to me you have a great system going; very efficient. I don't believe I could keep up with that many plants; the most I ever cared for at the same time is about 100 - 110, give or take a few. People used to freak when they visited, wondering how the heck I managed to care for so many plants, but it wasn't that hard. Plus, if you enjoy something as much as I enjoy plants, you somehow manage. Still. I've never been near where you are. Your collection is quite impressive.

Anonymous said...

Thank you, Mr. Subjunctive! That's impressive, and very useful.


Mae said...

I love how scientific you are. And I used to want to be like you, collecting all sorts of amazing plants. And I felt a little guilty that I wasn't as amazing as you. But now I don't. Because I don't want to water like that. Because I'm lazy and get bored easily. About 10 plants at a time is all I can manage.

Thanks for the details! (And for setting me free from my overwhelming goal of being as awesome as you are...)

Paul said...

Out of curiosity, do you use crystal soil or the similar gel packs or any other water-helper'products'? Also, do you use plain, ol' tap water or rain water or both?

I ask only because I've grown very suspicious of my tap water and how it seems to affect certain plants. I think it's due to the chloramine in the water (the stuff nearly smells like a swimming pool), but could be pH too.

mr_subjunctive said...


Just tap water; I would like to use rain water, but it seems like that would be adding yet another layer of lifting and complexity to a system that's already hard on my back[1] and complex.

I don't use any gel "crystal" or similar products; in fact, if I add anything to my regular potting mix, it's so that it will dry out faster (perlite, aquatic soil, gravel), not so it will stay wet longer.

As for water quality: Iowa City gets its water from the Iowa River, which is consequently fairly soft, though a little high in nitrates (fertilizer runoff from farms upstream). This was great for the aquarium (tropical fish usually favor softer water), and obviously the plants don't mind a little extra nitrogen.

When we moved, we moved to a town that gets its water from an aquifer. Most/all of Iowa used to be a sea bed, during the Devonian, so it's mostly limestone, which means that the new tap water is a lot harder. This has been problematic for the aquarium, but the only real difference for most of the plants is that they're a lot more likely to get water spots if I get the leaves wet during watering. Which is annoying, but with all the home renovation that's been happening here, everything's dusty all the time if I don't wet the leaves, so the plants are kind of screwed either way. I'm assured that the construction dust will stop very soon, but I've been hearing that for over a year now, so I no longer believe it.

The Cordyline fruticosas have done significantly less well since the move, which might or might not be related to water quality; some plants seem a lot more affected than others, which makes me think maybe the problem is more temperature than water.


[1] Though this is much less hard on my back than watering at the apartment was: the bottom of the bathtub in the plant room is roughly at waist level, instead of nearly at floor level, so there's a lot less bending over.

mr_subjunctive said...

Water Roots:

The thing people don't understand is how insidious it all is. You start out with a couple plants, and then you're in the store and you see another one that you find interesting, so you bring it home, and then if you have three it's not that hard to justify four or five, and then, oh! you can take cuttings of one of them, and so on and so forth until you wake up one day and you have fifty, two hundred, seven hundred, whatever. There should be warning labels on plants. (Yeah, dream on -- they can't even put proper ID labels on plants, half the time.)


Well, but if you can manage ten, then surely you have room for an eleventh plant. Just a small one, you know. . . .

cconz said...

Wow!! You really do have it down to a science. I'm impressed. I just have my bathtub filled with jugs of water and water every Thursday. You have a beautiful collection.

Unknown said...

A belated question: Have you considered wick watering for some of the plants? With large-ish/shared reservoirs, it might make things simpler in terms of plants that seem to need water constantly.

Kenneth Moore said...

I have the "oh shit" monitor. When my Alternanthera dentata goes limp, it's time to water the potbound or water-loving plants. After two or three such instances, everything else gets wet. But then, I don't quite have 100 plants, or I have about 120, depending on how you count them. Much easier to keep track of... But unlike Mae, I still want to be extremely obsessive and effective at taking care of plants, so I appreciate the expose!

CelticRose said...

I apologize if this is a double post -- Blogger was acting up when I tried to comment yesterday.

Impressive. Very impressive.

I could never keep up with that many plants. Most of my plants are cacti and other succulents because they can tolerate the occasional drought.

Anonymous said...

so when do nina and sheba get watered in the whole scheme of things? :P

Also, how do you think your water bill is affected (effected?) ?

mr_subjunctive said...


I hadn't really ever considered wick-watering, no. Thinking about it now that you've brought it up, mainly what strikes me is how much work it would be to convert things, and how much of a pain it would be to have to devote space to the plants and their water separately.

Kenneth Moore:

We sort of did that at work, with the Spathiphyllums. It wasn't 100% reliable, but it was a very visible signal.


My plant population more or less self-selects for the ability to handle an occasional drought. If I really like a plant, I'll try it a second or even a third time, but there are too many easily-growable plants out there to waste a lot of time on plants that aren't.


Sheba gets water twice a day, but never actually finishes it. Nina . . . I don't really have a system for watering the terrarium, actually. I water when it occurs to me that it needs water. I don't write it down, so I don't know how often that is, but I'm fairly certain it's less often than every 12-16 days. Maybe once a month.

No idea on the water bill. The landlord paid for water when we lived in the apartment, and the husband's dealt with the water bills since we moved into the house. I wouldn't even know where to start estimating.

Sentient Meat said...

Wow, cool. Thanks for documenting this. I think I have about 400 plants, mostly succulents, but I'm about to lose about a dozen adopted orchids to mealies and scale they brought with them. I tend to spray-irrigate them all at varying intervals depending on the heat and season.

You're quite systematic! I confess I had a bit of a "boredom/aversion" reaction to the details at first glance, but that's not a criticism--I think it's a natural reaction to another's intricate details, like reading a spreadsheet of a friend's exercise.

In actuality I'll probably bookmark this post for closer reading and borrowing later. Useful stuff!

Unknown said...

Yeah, it would be a pain.. There's also capillary mats, which may or may not be less trouble, depending on the sort of pots used.

Anyway, t'was just an idea.

mr_subjunctive said...

Sentient Meat:

Yeah, I kind of had that reaction while writing it, too.

Sentient Meat said...

Hi Mr S,

That's writer drive and discipline (not to mention gardener drive and discipline). It's hard to sit and document these things.