# Will a Red Worm Population Double in 3 Months?

One bizarre vermicomposting “fact” that has been floating around for years, and taken seriously by many newbie vermicomposters, is this idea of expecting your Red Worms to double in number in 3 months (or “90 Days”). It seems like a fairly reasonable claim on the surface – but if you really sit down and crunch the numbers you’ll realize pretty quickly just how utterly ridiculous it is!

For starters – even regardless of any fun calculations you can make (something we’ll do in a minute) – it’s hugely important to remember that Red Worm reproduction and growth are both HIGHLY dependent on a wide range of different factors. Some of the most important include 1) temperature, 2) moisture content, 3) population size, 4) food value and overall availability.

But just for fun, let’s crunch the numbers anyway!

For our little thought experiment, we are going to assume that we’re starting with

**100 adult Red Worms**

__Some Other Important Assumptions__

- Fairly close to “ideal” conditions – 25C / 77F temps – good moisture, ample nutrition etc

- 3 cocoons produced per adult worm per week*****

- 3 juvenile worms hatching from each cocoon*****

- 21 days incubation time until cocoons hatch*****

- 42 days to maturity*****

- 12 week period – with final tally being made at the END of these 12 weeks (still, technically a little less than 3 months)

- For sake of simplicity we are basically assuming that all cocoons are dropped at the end of each week – so each cohort will hatch/mature at the same time. This is obviously not how it would happen (cocoons would be laid throughout week) – so our final tallies are actually going to be lower than they should be.

- There are NO worm mortalities during the 12 weeks

*****These figures are based on those shared at the end of this post: Crazy Q&A Podcasts – Session #13 (most closely resembling the figures calculated by professional worm farmer, George Mingin)

__NOTE__: What is listed under each week is what we’ll expect to be present at the *beginning* of that week

__WEEK 1__100 Adults

__WEEK 2__100 Adults

300 Cocoons (A)

__WEEK 3__100 Adults

300 Cocoons (A) – 7 days old

300 Cocoons (B)

__WEEK 4__100 Adults

300 Cocoons (A) – 14 days old

300 Cocoons (B) – 7 days old

300 Cocoons (C)

__WEEK 5__100 Adults

900 Juveniles (A)

300 Cocoons (B) – 14 days old

300 Cocoons (C) – 7 days old

300 Cocoons (D)

__WEEK 6__100 Adults

900 Juveniles (A) – 7 days old

900 Juveniles (B)

300 Cocoons (C) – 14 days old

300 Cocoons (D) – 7 days old

300 Cocoons (E)

__WEEK 7__100 Adults

900 Juveniles (A) – 14 days old

900 Juveniles (B) – 7 days old

900 Juveniles (C)

300 Cocoons (D) – 14 days old

300 Cocoons (E) – 7 days old

300 Cocoons (F)

__WEEK 8__100 Adults

900 Juveniles (A) – 21 days old

900 Juveniles (B) – 14 days old

900 Juveniles (C) – 7 days old

900 Juveniles (D)

300 Cocoons (E) – 14 days old

300 Cocoons (F) – 7 days old

300 Cocoons (G)

__WEEK 9__100 Adults

900 Juveniles (A) – 28 days old

900 Juveniles (B) – 21 days old

900 Juveniles (C) – 14 days old

900 Juveniles (D) – 7 days old

900 Juveniles (E)

300 Cocoons (F) – 14 days old

300 Cocoons (G) – 7 days old

300 Cocoons (H)

__WEEK 10__100 Adults

900 Juveniles (A) – 35 days old

900 Juveniles (B) – 28 days old

900 Juveniles (C) – 21 days old

900 Juveniles (D) – 14 days old

900 Juveniles (E) – 7 days old

900 Juveniles (F)

300 Cocoons (G) – 14 days old

300 Cocoons (H) – 7 days old

300 Cocoons (I)

__WEEK 11__100 (original) Adults

900 Adults (A)

900 Juveniles (B) – 35 days old

900 Juveniles (C) – 28 days old

900 Juveniles (D) – 21 days old

900 Juveniles (E) – 14 days old

900 Juveniles (F) – 7 days old

900 Juveniles (G)

300 Cocoons (H) – 14 days old

300 Cocoons (I) – 7 days old

300 Cocoons (J)

__WEEK 12__100 (original) Adults

900 Adults (A)

900 Adults (B)

900 Juveniles (C) – 35 days old

900 Juveniles (D) – 28 days old

900 Juveniles (E) – 21 days old

900 Juveniles (F) – 14 days old

900 Juveniles (G) – 7 days old

900 Juveniles (H)

300 Cocoons (I) – 14 days old

300 Cocoons (J) – 7 days old

300 Cocoons (K)

2700 Cocoons (A-1)

__FINAL TALLY (END of WEEK 12 | Beginning of WEEK 13)__100 (original) Adults

900 Adults (A)

900 Adults (B)

900 Adults (C)

——————————–

900 Juveniles (D) – 35 days old

900 Juveniles (E) – 28 days old

900 Juveniles (F) – 21 days old

900 Juveniles (G) – 14 days old

900 Juveniles (H) – 7 days old

900 Juveniles (I)

——————————–

300 Cocoons (J) – 14 days old

300 Cocoons (K) – 7 days old

300 Cocoons (L)

2700 Cocoons (A-1) – 7 days old

2700 Cocoons (A-2)

2700 Cocoons (B-1)

—————————————————————–

__TOTALS__

**2800 Adults
5400 Juveniles
9000 Cocoons**

SO…

We’re looking at a potential 28-fold increase in the number of adults alone!

Of course, a typical worm bin *probably* won’t see growth rates like the ones shown above since people often start with a fairly large quantity of worms in a relatively small container. BUT, it really does give you some idea of what’s potentially possible if you give the worms plenty of space to spread out in, and just generally take good care of them!

Bottom-line – it’s safe to say that unless you are really messing up, you should definitely expect to see much more than “doubling” of your Red Worm population (especially if you are counting juveniles) within a few months!

Written by Bentley on September 9th, 2013 with
33 comments.

Read more articles on General Questions.

suzan garcia#1. September 9th, 2013, at 11:53 PM.

Bentley, I have a problem, there is something growing in 2 of my bins [worm factory]. It looks like a little plant, green & purple teardrop buds w/a lot of lacy roots. It’s growing on the inside corners & underneath the bins, hanging down. Looks scarey & I’m wondering if it will hurt the worms. Have you any idea what it might be & should i worry about it ??? Thank you, Suzan