Sort by folder size

Hello every one! I have this script:

$log = ".\logfile.log" 
$startFolder = "C:\VMs"
$colItems = Get-ChildItem $startFolder  | Where-Object {$_.PSIsContainer -eq $True} | Sort-Object
foreach ($i in $colItems){
   $itemSum = Get-ChildItem ("$startFolder\" + $i.Name) -recurse | Measure-Object -property length -sum"$startFolder\$i -- " + "{0:N2}" -f ($itemSum.sum / 1KB) + " KB" >> $log
   } 
import-csv $log -delimiter "`t" | export-csv .\TEST.csv
$body = Get-Content  $log | Sort |  Out-String
Send-MailMessage -From test@test.local -To test1@test.local -Subject "Test Theme" -attachment .\TEST.csv -Encoding ([System.Text.Encoding]::UTF8) -Body $body  -SmtpServer test123.test.local
Remove-Item $log
Remove-Item .\TEST.csv

When this script done I receive something like this in email message:

C:\VMs\Backup -- 0,00 KB

C:\VMs\Vbox -- 82 874 750,42 KB

C:\VMs\VMWARE_BACKUP -- 182 818,77 KB

How I can change this script to sort by folder size? Notalphabetically.

Thanks in advance!