Forum Discussion
Yes, I do agree with above discussion that wildcard ssl doesn't support root domain when you order for *.[rootdomain.com]
But this is the great news for you all because when your order your wildcard ssl from RapidSSL or GeoTrust Certificate authority then you are able to secure your root domain plus all sub domain under your root domain.
Here are the links where authority confirm this support
http://www.geotrust.com/ssl/wildcard-ssl-certificates/
Search for [Bonus: secure domain.com for free when you order *.domain.com] in this page
http://www.clickssl.com/ssl-certificates/geotrust/truebusinessid-wildcard (Platinum Partner of GeoTrust)
search for [*Bonus: When you are purchasing GeoTrust True BusinessID Wildcard for .yourdomain.com, then you will secure yourdomain.com at free of cost.]
I hope this little help may save your big money.
There are other Certificate Authorities also now in the market who offers Wildcard SSL Certificates at budget-friendly prices with the same technical features and benefits where you can protect the root domain and all connected subdomains on multiple servers.
Here are the links for the certificates
https://cheapsslweb.com/positive-ssl-wildcard
https://cheapsslweb.com/sectigo-positive-ssl-wildcard
This will save you at least 80% on every purchase.