Radiatively-driven natural SUSY (RNS) models enjoy electroweak naturalness at the $10%$ level while respecting LHC sparticle and Higgs mass constraints. Gluino and top squark masses can range up to several TeV (with other squarks even heavier) but a set of light Higgsinos are required with mass not too far above $m_hsim 125$ GeV. Within the RNS framework, gluinos dominantly decay via ${tilde g} to t{tilde t}_1^{*}, bar{t}{tilde t}_1 to tbar{t}{widetilde Z}_{1,2}$ or $tbar{b}{widetilde W}_1^-+c.c.$, where the decay products of the higgsino-like ${widetilde W}_1$ and ${widetilde Z}_2$ are very soft. Gluino pair production is, therefore, signalled by events with up to four hard $b$-jets and large ${ ot!!{E_T}}$. We devise a set of cuts to isolate a relatively pure gluino sample at the (high luminosity) LHC and show that in the RNS model with very heavy squarks, the gluino signal will be accessible for $m_{{tilde g}} < 2400 (2800)$ GeV for an integrated luminosity of 300 (3000) fb$^{-1}$. We also show that the measurement of the rate of gluino events in the clean sample mentioned above allows for a determination of $m_{{tilde g}}$ with a statistical precision of $2.5-5%$ (depending on the integrated luminosity and the gluino mass) over the range of gluino masses where a $5sigma$ discovery is possible at the LHC.
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